Edd date of conception
Calculate your due date: How to find your baby's due date
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First day of my last period
BabyCenter's Due Date Calculator
Use our pregnancy due date calculator by plugging in either the date of your last menstrual cycle or the date you know you conceived. The calculator will do the rest.
How is my due date calculated?
There are several ways your due date is determined. If you happen to know the day you conceived, you can count 38 weeks from that day to find your due date. (Human gestation takes about 38 weeks.)
But very few expectant moms know exactly when they conceived. Even if you only had sex once during your fertile period, you wouldn't conceive on that day unless you happen to be ovulating. Sperm can live for up to five days inside your fallopian tubes. So, it could be up to five days after you have sex that you release an egg (ovulate) and it gets fertilized by a waiting sperm. That's the day you conceive.
So, without knowing the day of conception, how does anyone determine a due date?
First day of your last period
The most common way to calculate your pregnancy due date is by counting 40 weeks from the first day of your last menstrual period (LMP). And that's how most healthcare providers do it.
If your menstrual cycle length is the average length (28-day cycle), your menstrual cycle probably started about two weeks before you conceived. This explains why pregnancies are said to last 40 weeks instead of 38 weeks.
This method doesn't take into account how long your menstrual cycle actually is or when you think you might have conceived. But generally speaking, women typically ovulate about two weeks after their menstrual cycle starts. And women are more likely to know when their last period started than the day they ovulated.
Conception date
If you do happen to know precisely when you conceived – say, if you were using an ovulation predictor kit or tracking your ovulation symptoms – you can calculate your pregnancy due date based on your conception date.
Just choose that calculation method from the pulldown above and put in your date.
Note: Again, you don't necessarily conceive on the day you have sex.
IVF transfer date
If you conceived through IVF, you can calculate your due date using your IVF transfer date. If you had a Day 5 embryo transfer, count 261 days from your transfer date. If you had a Day 3 embryo transfer, count 263 days.
Can my due date change?
Your healthcare provider might revise your due date if your baby is measured during a first trimester ultrasound scan and found to be much bigger or smaller than expected for gestational age. This is more likely to happen if you have an irregular menstrual cycle length that makes it hard to pinpoint the date of conception.
Your healthcare provider will measure your baby during that ultrasound exam to figure out how far along your baby is and then provide you with a new due date.
What if I already know my due date?
If you already know your due date, you can use this calculator to see your pregnancy timeline.
It will tell you when you'll hit various milestones, and when you may be due for prenatal tests and prenatal visits. You'll also find what your baby's sign and birthstone will probably be and which famous people were born on your due date.
How likely am I to give birth on my due date?
Of course, a due date calculation is always approximate, whether it's from our tool or from your doctor or midwife. Only 1 in 20 women delivers on their due date. You're just as likely to go into labor any day during the two weeks before or after.
Want more information about how the weeks, months, and trimesters of pregnancy are counted? See our pregnancy timing chart.
How soon can I take a pregnancy test?
With all this talk about pregnancy due dates, you may be wondering when you can take a pregnancy test. To ensure you get the most accurate reading, it's best to wait a few days after your missed period to take a pregnancy test.
At-home urine tests measure the amount of hCG (human Chorionic Gonadotropin) present in your body.
If you take a pregnancy test before you miss your period, you may not get an accurate result, despite what some tests advertise.
If you're getting a blood test in your provider's office, you may get results sooner. These tests also measure the amount of hCG in your bloodstream, but they're more sensitive than at-home urine tests. Blood tests may be able to detect pregnancy six to eight days after ovulation.
Read more
- Your pregnancy, week by week
- Your first trimester pregnancy checklist
- Pregnancy Weight Gain Calculator
- Ovulation Calculator
- See all tools
Due Date Calculator — Amazingly Accurate Pregnancy Calculator
First day of your
last period:Please choose the day your most recent period started.
Average cycle: 20 days21 days22 days23 days24 days25 days26 days27 days28 days29 days30 days31 days32 days33 days34 days35 days36 days37 days38 days39 days40 days41 days42 days43 days44 days45 days
or
Date you
conceived:
Conception is approximately two days after intercourse.
Already know your due date? Click here
Pregnancy Week by Week Universal Header
Pregnancy due date calculator video
Learn how to calculator your pregnancy due date in this video.
When is my baby’s due date?
So you got your positive pregnancy test, you’re feeling some early signs of pregnancy, and now you’re wondering, “when is my baby’s due date?” We’ve got you covered with the Mama Natural due date calculator!
Enter your information in the due date calculator above and discover the best estimate for when your little bundle of joy will make his or her appearance.
How does this due date calculator work?
Because you may not know exactly when you ovulated or conceived, a due date calculator will typically calculate your estimated due date based on your last menstrual period (LMP).
Our online due date calculator uses a simple method to calculate your due date.
- Your due date is estimated to be 40 weeks after the first day of your LMP
- Your cycle is assumed to be 28 days long, with ovulation occurring at day 14
- Therefore the calculator adds 280 days (40 weeks) to your LMP
This method of due date calculation is known as Naegele’s rule (more info on this below).
Due date calculator quote Our standard due date calculator adds 280 days (40 weeks) to the date of your last menstrual period (LMP)
My cycle isn’t 28 days. Will this due date calculator work for me?
Yes.
The logic behind our pregnancy calculator works as follows:
- The average cycle length is 28 days
- If your cycle length is shorter, your due date will be earlier
- For every day your cycle is shorter, your due date moves one day earlier
- Similarly, if your cycle is longer, your due date will be later
- For every day your cycle is longer, your due date moves one day later
What is the date of conception due date calculator illustration
How do you calculate due date from conception?
If you know when you conceived, our pregnancy calculator calculates your due date by adding 38 weeks to the date of conception. This method of calculation may be more accurate than a LMP due date calculation if you have irregular or consistently longer or shorter cycles than 28 days.
What exactly
is the date of conception? The date of conception is the day that the egg and sperm meet.
Women who track their ovulation may know their exact date of conception. But for many women, date of conception can be tricky to pinpoint.
Sperm can live in a woman’s body for up to five days, and the ovum (egg) can live for up to 24 hours after being released. In other words, you have a six-day window where you could potentially get pregnant each month.
Do you already know your due date but want to know when you likely conceived? Try our reverse due date calculator.
What is an estimated due date (EDD)?
An estimated due date (EDD) is a “best guess” as to when baby might be born based on a due date calculator like this one.
However, only 4% of babies are born on their due date! Whereas 80% of babies are born within the window of two weeks before and two weeks after your due date calculator results. (See “due month” section below.)
Baby due date on a calendar with pregnant woman background – only 4% of babies are born on their due date
What is “gestational age?” Can it be different than what the calculator shows?
Gestational age (GA) is the term used to describe how far along the pregnancy is and how long baby has been gestating (growing in the uterus).
If you get an ultrasound you may notice a “GA” on the image with a number of weeks and days. This figure is based on how the baby is measuring, not on your LMP, which the due date calculator uses.
It’s normal for these dates to not match up perfectly. If there are significant differences in the dates, your doctor may want to dig deeper to determine conception date. As a result, your midwife or doctor may change your due date based on the ultrasound gestational age.
Early ultrasounds are very accurate when dating a pregnancy and can be helpful if you don’t know your LMP or your periods are irregular.
Note that you don’t have to have an early ultrasound, especially if you are fairly certain of your cycle length and conception window. This study shows that early dating ultrasounds don’t change the incidence of induction.
How are the weeks of pregnancy calculated?
The 40 weeks of pregnancy begin on the first day of your last menstrual period.
This can be a little confusing because, for most people, conception doesn’t occur until day 14 of the menstrual cycle. So yes, you aren’t actually pregnant during those first two weeks of pregnancy.
Here’s a more in-depth answer to that perennial question of How many weeks pregnant am I?
What is a
“due month?”A “due month” is a more accurate timeframe for when you can expect to deliver your baby. Only 4% of babies are born on their due date. Whereas 80% of babies arrive either two weeks before the due date or two weeks after. Hence the term “due month.”
The length of a natural pregnancy can vary by as much as five weeks. (source)
A due month helps some mamas reduce the stress and fear of going past their due date.
To calculate your due month, simply subtract two weeks from your EDD given by your practitioner or our due date calculator and also add two weeks to your EDD.
Voilà, your due month!
Yet another way to handle this tricky business of calculating your pregnancy calendar is to add two weeks to the end of your EDD and say, “Baby will be here before [that date].”
What is Naegele’s rule for due date calculation?
Naegele’s rule is what this due date calculator and pregnancy calendar is based on. Named after a German Obstetrician who practiced in the early 1800’s, Naegele’s rule predicts childbirth to occur 280 days after the first day of the last menstrual period.
However, Naegele’s rule assumes that your cycle is 28 days long with ovulation occurring on day 14, which isn’t the case for many women. So other ways of calculating your due date may be more accurate.
(How accurate is your due date? Find out in this post.)
Modern data suggests that women have their babies a few days after their due date on average. Studies like this one found that Naegele’s rule consistently places the due date about 2-4 days too early.
So a better estimate may be 40 weeks and 3 days from LMP.
Alternatively, you can use our Advanced Due Date Calculator, which uses the Mittendorf-Williams rule to calculate your due date, which has been shown to be more accurate.
Due date calculator quote 2 Modern data suggests that Naegele’s rule places the due date about 2-4 days too early
What’s the Mittendorf-Williams rule?
This study done in 1990 showed that pregnancy lasted an average of 288 days past LMP for Caucasian first-time moms. For Caucasian women who were not first-time moms, their date of delivery averaged 283 days past LMP (3 days after Naegele’s rule predicted). This finding is known as the Mittendorf-Williams rule.
While Naegele’s rule is still the most widely used formula for a due date calculator, the Mittendorf-Williams rule is proving to be more accurate. But it’s a much more complex calculation, taking into account:
- Maternal age
- Race
- Height
- Weight
- Number of pregnancies
- Average luteal phase length
- Maternal education
- Alcohol during pregnancy
- Coffee during pregnancy
Our Advanced Due Date Calculator uses the Mittendorf-Williams rule.
Related Resources
- Our FREE Natural Pregnancy Week-By-Week Series ?
- My Bestselling Natural Pregnancy Guide ?
- Reverse Due Date Calculator ◀️
- Natural Birth Stories ??
- Baby Name Finder ?
Ready to calculate your due date?
First day of your
last period:Please choose the day your most recent period started.
Average cycle: 20 days21 days22 days23 days24 days25 days26 days27 days28 days29 days30 days31 days32 days33 days34 days35 days36 days37 days38 days39 days40 days41 days42 days43 days44 days45 days
or
Date you
conceived:Conception is approximately two days after intercourse.
Already know your due date? Click here
〚 Pregnancy calculation.
How to determine the date of birth? 〛|| BABYSTART Blog February 11, 2020
Most pregnancies last around 40 weeks (or 38 weeks from conception), so generally the best way to determine due date is to count 40 weeks or 280 days from the first day of your last period (LMP) . Another way to do this is to subtract three months from the first day of your last period and add seven days. So if your last period started on April 11th, you would count down three months to January 11th and then add seven days, which means your due date should be January 18th. This is how your doctor will estimate your due date - and that's a pretty solid goal. But remember: delivering a week or two before or after is just as normal.
Date of conception
Calculating due date based on the first day of your last period works well for women with relatively regular menstrual cycles. But if your cycle is irregular, the LMP method may not work for you. Because a reliable estimated due date (EDD) is important, you and your doctor can use your conception date if you remember it.
Just add 266 days to get an estimate.
IVF transfer date
According to the Centers for Disease Control and Prevention (CDC), more than 250,000 assisted reproductive technology cycles are performed each year in the United States, resulting in about 77,000 or more babies born each year. If you are part of a growing tribe of IVF moms, you can more accurately calculate your due date using the IVF transfer date.
Ultrasound Scan
Even if you can't pinpoint when you conceived, forgot the day of your last period, or aren't sure when you ovulated, other clues can help you and your doctor determine your due date at your first pregnancy appointment, including :
Early ultrasound, which can more accurately determine the date of pregnancy. However, keep in mind that not all women get an early ultrasound. Some practitioners do them regularly, but others recommend only one if your periods are irregular, you are 35 or older, you have a history of miscarriage or pregnancy complications, or the due date cannot be determined based on your physical examination and LMP.
Pregnancy milestones, such as the first time the baby's heartbeat is heard (around 9 or 10 weeks, although this may vary) and when you first feel the baby move (between 18 and 22 weeks on average, but this may be earlier or later) may give clues as to whether your due date is accurate.
Your fundal height, which is measured from your pubic bone to the top of your uterus, is checked by your doctor at every prenatal visit and helps confirm your due date.
The size of your uterus, which will be noted during your initial internal pregnancy test, can also be a factor in determining EDD.
Can I schedule my due date?
Whether you're trying to avoid a midsummer pregnancy or you're a teacher who wants to have the most fun with your baby, you can try to determine when you'll get pregnant to "plan" your due date. But even if you're one of those lucky ones who can get pregnant when she really wants to, just remember that you probably won't be able to pinpoint exactly when you'll give birth a day (or even a week).
or a month!)
Can the due date change a lot?
Yes, your due date may change. While this is definitely not a cause for concern, your doctor may change your due date for a number of reasons as your pregnancy progresses. Maybe you're having irregular periods and an early ultrasound date was cancelled, or that your first ultrasound was in your second trimester. It may also be because you have abnormal growth or abnormal levels of alpha-fetoprotein (AFP), a protein produced by your baby. Talk to your practitioner if you have any questions or concerns.
🎖▷ Why You Don't Have to Worry About Weight Gain with Lamictal
Psychology
2 minutes read
If you're worried that taking Lamictal (lamotrigine) might cause weight gain, there's good news. It probably won't affect your weight much. If anything, you're more likely to lose weight due to Lamictal than gain weight, but either way, the changes are likely to be pretty small.
The effect of Lamictal on weight has been little studied, and various clinical trials have found minimal effect. In fact, some researchers even considered the drug as a possible remedy for obesity and as a remedy for overeating. This information should be reassuring for people with bipolar disorder, as many of the medications used to treat this condition can cause weight gain.
Lamictal findings and weight gain or loss
Lamictal is an anticonvulsant that can be used to treat seizures such as epilepsy. It is also used as a mood stabilizer for bipolar disorder.
In the first clinical trials with the drug, 5 percent of adults with epilepsy lost weight while taking Lamictal, while 1 to 5 percent of patients with bipolar I disorder gained weight while taking the drug. The researchers do not disclose how much weight patients have gained or lost.
Meanwhile, a 2006 study comparing the effects on weight of Lamictal, lithium, and placebo found that some Lamictal-treated patients gained weight, some lost weight, and most remained about the same weight.
Weight changes are usually not many pounds anyway. Obese patients taking Lamictal lost an average of four pounds, while the weight of non-obese patients remained virtually unchanged.
Relationship between weight gain and other bipolar drugs
Weight gain from medications used to treat bipolar disorder is unfortunately quite common. Some mood stabilizers commonly used for bipolar disorder, especially lithium and Depakote (valproate), carry a high risk of weight gain.
In addition, the atypical antipsychotics Clozaril (clozapine) and Zyprexa (olanzapine) tend to cause significant weight gain in people who take them. Finally, some antidepressants, notably Paxil (paroxetine) and Remeron (mirtazapine), have been associated with weight gain.
Therefore, if you are already overweight, you and your psychiatrist may want to consider additional weight gain when determining your bipolar medication regimen. Based on this, Lamictal may be a good choice.
Lamictal as a possible treatment for obesity
Lamictal has also been studied as a possible treatment for obesity in people without epilepsy or bipolar disorder.
In a small 40-person clinical trial conducted in 2006, researchers randomly assigned participants to receive either lamiktal or placebo for up to 26 weeks. Each participant in the study had a body mass index (BMI) between 30 and 40, placing them in the obese group to the level of severe obesity. Those who took Lamictal lost an average of just over 10 pounds. Those who took the placebo lost about 7 pounds in the meantime, so while those who took Lamictal lost more weight, they didn't lose all that much more.
Another study in 2009 looked at Lamictal as a remedy for overeating. This study involved 51 people with the condition that 26 of them received Lamictal, and 25 - placebo.
Those who took Lamictal lost more weight than those who took placebo (about 2.5 pounds vs. about one third of a pound) and did have significant improvements in blood sugar and cholesterol lab test results. However, Lamictal did not appear to affect other aspects of the eating disorder when compared to placebo.
