How long till pregnancy test shows

Doing a pregnancy test - NHS

If you have missed a period and recently had unprotected sex, you may be pregnant. Pregnancy tests are most reliable from the first day of your missed period.

When you can do a pregnancy test

You can carry out most pregnancy tests from the first day of a missed period. If you don't know when your next period is due, do the test at least 21 days after you last had unprotected sex.

Some very sensitive pregnancy tests can be used even before you miss a period.

You can do a pregnancy test on a sample of urine collected at any time of the day. It doesn't have to be in the morning.

Where you can get a pregnancy test

You can buy pregnancy testing kits from pharmacists and some supermarkets. They can give a quick result and you can do the test in private.

The following places provide free pregnancy tests:

sexual health services
some young people's services – call the national sexual health helpline on 0300 123 7123 for details
Brook centres for under-25s – find your nearest Brook centre

You may also be able to get a pregnancy test free of charge from your GP.

How does a pregnancy test work?

All pregnancy tests detect the hormone human chorionic gonadotrophin (hCG), which starts to be produced around 6 days after fertilisation.

Most pregnancy tests come in a box that contains 1 or 2 long sticks. You pee on the stick and the result appears on the stick after a few minutes. All tests are slightly different, so always check the instructions.

Will a pregnancy test work if I'm on the pill?

Yes.

Some methods of contraception, such as the contraceptive pill, contain hormones, but these hormones will not stop a pregnancy test working.

No method of contraception is completely effective, so it's important to take a pregnancy test if you think you might be pregnant.

Pregnancy test results

Home pregnancy tests are accurate as long as you follow the instructions correctly.

A positive test result is almost certainly correct. However, a negative test result is less reliable.

The result may not be reliable if you:

do not follow the instructions properly
take the test too early

Some medicines can also affect the results.

If you get a negative result and still think you're pregnant, wait a few days and try again. Speak to your GP if you get a negative result after a second test but your period has not arrived.

Continuing with the pregnancy

If you're pregnant and want to continue with the pregnancy, contact your GP or a midwife to start your antenatal care. You can use the pregnancy due date calculator to work out when your baby is due.

If you're not sure you want to be pregnant

If you're not sure about continuing with the pregnancy, you can discuss this confidentially with a healthcare professional. Your options are:

continuing with the pregnancy and keeping the baby
having an abortion
continuing with the pregnancy and having the baby adopted

As well as a GP or a nurse at your GP surgery, you can also get accurate, confidential information – from the age of 13 – from the following:

sexual health services
the MSI Reproductive Choices website
the British Pregnancy Advisory service website
the National Unplanned Pregnancy Advisory service website

All these services – including community contraceptive clinics – are confidential. If you're 13 or older, the staff won't tell your parents. They'll encourage you to talk to your parents, but they won't force you.

If you're under 25 and would prefer advice specifically for young people, the sexual health charity Brook provides a range of services for young people. The Brook website contains information on pregnancy choices. You can also use the Ask Brook 24/7 service.

Video: Is the pregnancy test accurate?

In this video, a midwife explains when you can take a pregnancy test and how to do it properly.

Media last reviewed: 5 February 2020
Media review due: 5 February 2023

Page last reviewed: 9 February 2022
Next review due: 9 February 2025

How early can home pregnancy tests show positive results? | Your Pregnancy Matters

What can we help you find?

Refine your search: Find a Doctor Search Conditions & Treatments Find a Location

Appointment New Patient Appointment
or Call214-645-8300

MedBlog

Your Pregnancy Matters

June 28, 2022

Your Pregnancy Matters

Robyn Horsager-Boehrer, M. D. Obstetrics and Gynecology

Home pregnancy tests can be very accurate if used properly.

Since the earliest recorded history, women have had a strong desire to know whether they are pregnant as early as possible. The body goes through countless changes in the first trimester, and one of the first indicators is a change in the hormones that leave the body through urine.

Ancient Egyptians relied on a form of urine testing to determine pregnancy status way back in 1350 BCE. A woman urinated daily on wheat or barley seeds and if the plants grew, it meant she was pregnant. Modern-day validation suggests that test was about 70% accurate in detecting human chorionic gonadotropin (hCG), a hormone produced by a woman’s body soon after implantation of a fertilized egg inside the uterus.

Thankfully, urine-based pregnancy tests have evolved substantially. Women now have access to advanced tests that can detect a pregnancy as early as eight days after ovulation. But while many home pregnancy tests are marketed as simple and effective, getting accurate results comes down to how early in your ovulation cycle you take the test.

Ovulation generally occurs around day 15 of a 28-day cycle. In a normal pregnancy, an egg is fertilized in the fallopian tube and then travels into the uterus, where it implants in the uterine wall. After implantation, production of hCG starts from cells in the developing placenta (tissue that will feed the fetus). Trace levels of hCG can be detected as early as eight days after ovulation.

That means you could get positive results several days before you expect your period to start. However, the first part of your cycle is more variable than the second, making it tricky to determine the best time for an early test.

“Thankfully, pregnancy tests have evolved substantially since the 20th century. Women now have access to advanced tests that can detect a pregnancy as early as eight days after ovulation.”
– Robyn Horsager-Boehrer, M.D.

When to take a home pregnancy test

The length of time from the first day of a period to ovulation can vary by several days from month to month. Sexual activity around ovulation leads to the possibility of fertilization of an released egg by sperm. But even then, the time frame for a fertilized egg to implant can vary. And hCG isn’t produced until after implantation has occurred.

For the most accurate results, we recommend testing in the morning on the day you expect your period to start. This allows for variability in the timing of ovulation, fertilization, and implantation. Testing in the morning provides a more concentrated urine sample.

Follow the directions carefully to get the best results. Before you take the test, make sure you understand what the readout for “pregnant” and “not pregnant” will be. Some tests still use two lines to indicate you are pregnant and one to indicate that you aren’t. However, many tests have switched to words such as “yes” and “no”, or “pregnant” and “not pregnant” for additional clarity.

Related reading: Is it OK to use a hot tub during early pregnancy?

Pregnancy test accuracy

Each type of pregnancy test is designed to detect a set minimum level of hCG. This is why pregnancy test manufacturers advertise the way they do: “Know four days sooner,” or “Accurate up to six days before a missed period.” However, while home pregnancy tests are quite accurate – many boast a 99% detection rate based on laboratory testing results – marketing claims can be misleading.

For example, a 99% detection rate means a test can detect hCG 99% of the time on the day you miss your period. These statistics also assume that women are testing at the optimal time and following all instructions correctly.

Many home pregnancy tests available today are midstream urine dip tests, which are the traditional “pee-on-a-stick” tests and are fairly easy to use. There also are tests in which you pee into a cup and dip a test strip into the urine. The New York Times published a story ranking the best home pregnancy tests, citing a midstream test with an ergonomic grip as the easiest to use and most accurate.

Research has shown that average test results when women used the dip tests matched lab test results just 70% of the time, whereas 99% of women typically can get an accurate reading from a midstream test.

False positive and negative results

When a test result is inaccurate, it’s either a false negative (the test says you are not pregnant, but you are) or a false positive (the test says you are pregnant, but you aren’t). Several factors can cause false negative results:

Having too dilute urine after drinking a lot of water or testing later in the day.
Testing too soon when there has not been enough time for a fertilized egg to implant and start hCG production.
Using a pregnancy test that doesn’t detect lower levels of hCG. You can check the package insert for more information about the level at which the test will be positive.

Sometimes an egg will implant briefly but will not be sustained. This is also called a chemical pregnancy – hCG is produced, but the pregnancy doesn’t continue. A test performed several days before an expected period can show a positive result, but the woman still gets her period soon or on time. Rarely, certain tumors can produce hCG, causing a pregnancy test to be positive even when a woman is not pregnant.

Related reading: It's not your fault: Understanding miscarriage

When to see a doctor

Most women who have a positive pregnancy test should wait a week or two before calling the Ob/Gyn office for a pregnancy blood test or ultrasound to confirm the pregnancy. We suggest waiting because the rate of early pregnancy loss is high, and it’s possible that you might have had a chemical pregnancy.

However, women with a history of ectopic pregnancy or current abdominal pain should call the doctor right away to be examined. Ectopic pregnancies implant outside of the uterus and produce hCG, resulting in positive pregnancy tests. However, these pregnancies can cause abdominal bleeding and prompt medical care is necessary. Women who have congenital heart defects or other chronic physical or mental health conditions should also see a doctor right away because treatment plans or medications might need to be altered to protect the woman and the fetus.

Advances in home pregnancy tests give women greater insight into what’s going on in their bodies sooner than ever before. No matter what your childbearing plans might be, it’s essential to get quick, accurate results at home to plan your next steps accordingly.

To visit with an Ob/Gyn, call 214-645-8300 or request an appointment online.

When to do a pregnancy test? Maternity hospital Leleka | Blog

Pregnancy in the life of every woman is a significant event and most often unexpected.

But, even if the pregnancy came as a “surprise”, you must definitely confirm your suspicions or refute them. And you can do this with the help of an instant express pregnancy test, in a matter of seconds.

Express pregnancy test is a very convenient, fast and inexpensive device that determines pregnancy (if any) as accurately as possible.

The erroneous result is reduced to a minimum and is only 1%.

The most informative are digital and tablet tests (the strip is placed on a plastic device with two "windows"). However, strip tests remain the most popular, which means that the price of the test does not affect the result.

If there is any doubt after the test, you should make an appointment with a gynecologist.

How the pregnancy test works

Despite the whole range of pregnancy tests, the principle of action is the same for everyone - to determine the level of hCG (the first hormone of pregnancy) in the urine.

hCG - secreted by the villi of the embryo from the period of attachment of the fertilized egg to the uterine wall.

May be detected in the urine and blood of a pregnant woman.

Pregnancy test procedure

Pregnancy test is performed no earlier than the first day of missed period or approximately 2 weeks after the expected day of conception. Until the zygote attaches to the wall of the uterus, hCG is not released, which means that before ten days of pregnancy, it is not advisable to carry out a test or any other tests.

At the beginning of the test, you should carefully study the instructions for its use. Although the principle of operation is always identical: one part of the test (paper) is immersed in a container with urine, the other (with a chemical indicator) determines the result in the form of red / blue stripes, the symbols “+” / “-” or the words “yes” / “no” ". The result is evaluated after the time specified in the instructions (from 1 to 5 minutes).

Sometimes there are mini-pipettes for metered distribution of urine in the tests, which are very convenient to use.

But putting the test under the urinary stream is not recommended, since this method can technically disrupt the express screening and give an error.

You cannot rely on the result of a single test; for complete certainty, you need to repeat the express test in 1-3 days.

If two stripes are determined each time, it is mandatory to make an appointment with a gynecologist.

When to take a pregnancy test

In order not to be confused by the numbers, dates and know exactly when it is appropriate to take a pregnancy test, you need to keep a calendar, control your well-being and know the basic process of how the egg is fertilized .

In every woman with a regular monthly cycle, the egg goes through several physiological stages of development, one of which is called “ovulation”.

Ovulation is the process where a mature egg is released from the ovary into the fallopian tube to join the sperm. If there is no sperm in the tube, the egg dies and menstruation occurs.

Ovulation lasts approximately 2 days. All this time the egg is active.

If during ovulation the spermatozoa were inside the woman's genitals and conception did occur, the fertilized egg (zygote) begins to "move" into the uterine cavity, with the help of the ciliated epithelium and the muscles of the fallopian tube itself.

This whole process takes about 1 week.

After a fertilized egg enters the uterine cavity, it attaches there, hCG rises in the blood, cells divide and further development of the fetus occurs.

The level of hCG (the first hormone of pregnancy) rises only after the fixation of a fertilized egg in the uterine cavity.

Therefore, a reliable result of pregnancy can be obtained only on the seventh to tenth day of conception.

In this case, the result must be supported by a doctor's opinion.

Some rapid tests can determine the presence of the hormone as early as the fourth day, but it is still better to check after at least 1.5 weeks. Then the level of the hormone becomes high enough to confidently determine the condition of the woman.

Delayed periods do not always indicate pregnancy, but it is better to immediately check the cause and take a test on the first day.

When is a pregnancy test false?

Two strips on the test do not always cause delight in women, since pregnancy is not a cherished dream for all women, for most it is a surprise.

However, if you really do not plan a child and your test suddenly becomes “striped”, do not rush to panic, since a result error is not ruled out here.

False-positive or false-negative responses can range from a technical failure of a screening test to the identification of serious gynecological pathologies.

As you can see, pregnancy is not the most “terrible” thing that a test can determine, so we once again emphasize the importance of a gynecological examination.

Gynecologists of the private maternity hospital "Leleka" strongly recommend not to be limited to the results of a rapid test to establish pregnancy.

Fetal development must be confirmed/denied at the appointment with a specialist.

Since today there is a growing trend of ectopic pregnancies, which lead to serious complications and gynecological pathologies in the future.

Be that as it may, a positive test result is only the first step towards determining pregnancy. The second step is a visit to the gynecologist, who must confirm / refute the information received. Since there are situations when express screening gives a false positive answer.

Main causes of a false positive result

A false positive result is a result that indicates the presence of pregnancy, in the absence of it.

Causes:

1. Incorrect express test.

Incorrect use of the test is the main cause of a false positive response. Therefore, you always need to read the instructions and follow the specified algorithm of actions. The evaluation of the result should be carried out strictly within the specified time range, from 3 to 10 minutes. After this period, a weak second strip may appear on the test (due to evaporation of urine), and the woman will perceive the result as a pregnancy.

2. Marriage.

A defective test is a very rare occurrence, but no one is immune from such a situation. Knowing this, women buy several tests from different brands and thus the problem is leveled.

3. Postpartum period.

Pregnancy test remains positive throughout pregnancy and 3-4 weeks after delivery. Therefore, if the test after the recent birth of a child shows a positive answer, and you are not planning children of the same age, you should not worry. However, you still need to check with your doctor about the absence of pregnancy.

4. Miscarriage, abortion.

After a miscarriage, miscarriage or medical abortion, the level of hCG cannot immediately decrease, it takes time. And, as a rule, this process takes from 2 to 4 weeks. Therefore, doing a pregnancy test during this period simply does not make sense, since the result will be false positive.

If in doubt, a blood test for hCG levels or a follow-up abdominal ultrasound should be done.

5. Preparation for IVF.

Some women dream of pregnancy so much that they take tests even when they don't have to. As, for example, when preparing for IVF.

During this period, ovulation is stimulated with hormonal preparations, which also increase the level of hCG, although there is no pregnancy itself yet. Therefore, a pregnancy test done during this period can misinform a woman.

6. Oncopathology.

Sometimes a positive pregnancy test, in its absence, indicates serious pathological processes that increase the level of hCG. These are ovarian tumors, lung, brain, breast or stomach cancer.

To dispel all suspicions and fears, with a positive pregnancy test result, you should immediately contact a gynecologist to rule out ectopic pregnancy and oncopathology.

Main causes of a false negative test

A false negative is a result that indicates no pregnancy, if any.

Causes:

Fertilization occurred before the start of menstruation, and the level of hCG did not have time to rise to the desired concentration.
There is a threat of miscarriage.
A woman is taking diuretics (diuretics).
Technical damage to the test.

If a pregnancy test shows a negative result, but the woman has specific pregnancy symptoms (morning sickness, dizziness, frequent urination, pain in the lower abdomen and chest), you need to see a doctor.

What to do if in doubt?

There are situations that make a woman doubt the correctness of a pregnancy test. For example, different tests give different results, spotting is present (similar to menstruation), screening gave a positive response, and there are no specific symptoms of pregnancy.

What to do in this case?

Do not look for the cause yourself, but go for a consultation with a gynecologist and approach the solution of the problem comprehensively.
Do not dispose of unwanted and unconfirmed pregnancies yourself.
Find the exact reason why the test showed a false positive result in the absence of pregnancy.

Note!

Leading gynecologists of the private maternity center "Leleka" strongly recommend that after passing the test with a positive response, immediately contact a medical institution.

Even if you do not plan to give birth to a child, pregnancy in any case must be confirmed or denied.

You should not rely only on the test result, and in no case should you resort to criminal abortions, buy the “necessary” pills in a pharmacy on your own, use folk methods to terminate a pregnancy.

All this is fraught with serious consequences and complications, even death.

The Leleka maternity hospital is a modern medical institution where you will always receive specialized, highly qualified obstetric-gynecological and neonatological medical care at the level of world standards.

Only timely diagnosis and competent treatment will help preserve the reproductive health of a woman and there are no other options here.

How and when to take a pregnancy test to get an accurate result

November 27, 2018LikbezZdorovye

Even an ideal test will lie if you break simple rules.

Express pregnancy tests today can be bought in every pharmacy, and even at the supermarket checkout. They are easy to use and reliable: doctors rate their accuracy at 99%. But often such tests lie.

How pregnancy tests work

Absolutely all pregnancy tests check whether urine or blood (if we are talking about a laboratory test) contains a special hormone - human chorionic gonadotropin, abbreviated hCG. It begins to be produced immediately after the fertilized egg attaches to the wall of the uterus.

If there is no pregnancy, there is nowhere to get hCG. If it is, hCG will be required.

The egg usually attaches to the uterus six days after fertilization. During this period, the test is meaningless: it will not show anything. But then the level of hCG increases rapidly, doubling every 2-3 days.

When to take a pregnancy test

Already 8 days after ovulation, during which the egg meets its sperm, the level of hCG becomes sufficient so that pregnancy can be detected using a laboratory blood test.

In a few more days - that is, on the 10-12th day after fertilization - the usual pharmacy tests will also detect pregnancy.

Although the instructions for many of them promise an accurate result already on the first day of delay, doctors advise not to rush. The reason is simple.

If you ovulated on the 10-14th day of the cycle, then by the beginning of the next cycle, at least 13 days will pass from the moment of fertilization. So, the test will signal you with two stripes.

However, ovulation may be delayed. If the egg was released on the 22nd day of the cycle, then by the beginning of the delay, the actual gestational age may be less than 7 days. This means that even ideal tests will most likely not fix anything.

If your cycle is more or less than 28 days, it's even more confusing.

Therefore, in order to get the most accurate result, it is worth waiting 5-7 days from the start of the delay.

If you are pregnant, the level of hCG by this point in any case will be such that even the cheapest tests with low sensitivity will unequivocally recognize it

But even if you have met all the deadlines, the test can still mislead you. For example, it will not see a high level of hCG and will show a negative result with an existing pregnancy, or, on the contrary, it will give out two strips, although it does not smell like a pregnancy. In fairness, let's say that this is not so much the fault of the test as you yourself.

Why express pregnancy tests lie

1. You used an expired or spoiled test

Rapid tests contain special highly sensitive substances that react to the level of hCG. It is they who, upon contact with the urine of a pregnant woman, are painted in a bright second stripe or plus sign.

But if the test is out of date or stored incorrectly, the sensitivity of these substances may decrease. As a result, they will give a negative result, which may turn out to be false.

What to do

Buy tests only in pharmacies, where, unlike supermarkets, they try to ensure the correct storage conditions. When buying, be sure to check the expiration date.

2. You bought a test with low sensitivity

The sensitivity of rapid tests is indicated by numbers - 10, 20, 25, 30. These numbers indicate the concentration of hCG in the urine (in mIU / ml) that they are able to capture. The higher the number, the less accurate the test. The most expensive and accurate options have a sensitivity of 10. But the cheap ones may not catch hCG and deceive you by showing a negative result.

What to do

When buying a test, be sure to check with the pharmacist how sensitive it is. Also, this information can often be found on the packaging and always in the instructions.

3. You took the test in the afternoon

Not for nothing that in the instructions for the vast majority of tests, the manufacturer talks about morning urine. It is more concentrated, there is more chorionic gonadotropin in it, which means that the test will be more reliable.

In the afternoon, the content of hCG in the urine is lower.

What to do

Use the test only in the morning, as directed by the manufacturer.

4. You drank a lot of water before taking the test

Water dilutes urine, which lowers hCG levels. A rapid test may not detect the hormone and give a false negative result.

What to do

Try not to eat or drink anything before the test.

5. You looked at the results at the wrong time

The instructions for each test stipulate the rules for its use. For example, like this: “The result can be assessed 4-5 minutes after the test, but no later than 15 minutes.” These minutes are not taken from the ceiling.

The lower limit indicates the time it takes for the test to react to the hCG level of the sensitive substances contained in it. If you look at the test earlier than the agreed time, the second strip (or the plus sign in the corresponding box) may not yet appear and you will see a false negative result.

If you look at the strip later than the time indicated as the upper limit, you risk getting a false positive result. Evaporated urine may leave a line that is easily confused with a second strip.

What to do

Before using the test, read the instructions and follow them strictly.

6. You are taking certain medications

Some diuretics and antihistamines affect the composition of urine by diluting it. This reduces the level of hCG, which means there is a risk of getting a false negative result.

Other drugs, on the other hand, may give you two strips when you are not pregnant. Such medicines include:

certain tranquilizers and sleeping pills;
anticonvulsants;
fertility enhancing drugs.

What to do

If you are taking any of the drugs on this list, do not rely on the paper rapid test. To establish pregnancy or its absence, do a laboratory blood test.

7. You are sick

If there is too much blood or protein in the urine, this can also affect the result of the rapid test. But here it is important to note that in itself this situation is extremely unhealthy. Blood in the urine indicates abnormalities in the functioning of the bladder or kidneys, increased protein indicates internal inflammation.

Therefore, it is most likely that an incorrect two strips on the test will be accompanied by fever and / or discomfort in the genital area and kidneys.

What to do

Do not rely on the rapid test if you have a fever, lower back or stomach pain. With such ailments, it is necessary to contact a therapist, gynecologist or urologist as soon as possible so as not to miss a serious illness.

8. You develop an ovarian tumor

Some tumors can trick the test into showing two lines.

What to do

After receiving a positive result, do not delay your visit to the gynecologist. The doctor will conduct studies during which he will establish the actual gestational age (if any) or send you for additional tests and to specialized specialists.