If i conceive today when will i be due

The Due Date Calculator estimates the delivery date of a pregnant woman based on her last menstrual period (LMP), ultrasound, conception date, or IVF transfer date.

Estimate Based On:First Day of Your Last Period:Average Length of Your Cycles:Ultrasound Date:Length of Pregnancy
at the Time:Transfer Date:Embryo Age:

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Estimation of due date

The due date, also known as the estimated date of confinement, is an estimation of when a pregnant woman will deliver her baby. While the due date is often estimated as a single date, it can be helpful to consider a range of due dates, since only 4% of births occur on the estimated due date.1

Due dates can be estimated using a number of different methods, including the last menstrual period, ultrasound, conception date, and IVF transfer date.

Last menstrual period

The default for this calculator bases the calculation on a woman's last menstrual period (LMP), under the assumption that childbirth on average occurs at a gestational age (age of a pregnancy calculated from the woman's last menstrual period) of 280 days, or 40 weeks. Although there is some debate regarding when pregnancy technically begins, whether at fertilization of the egg (conception), or when the egg adheres to the uterus (implantation), gestational age does not vary based on different definitions of pregnancy since it is based on LMP. In terms of gestational age, pregnancies typically last between 37 and 42 weeks, with 40 weeks often being used as an estimate in calculations. Thus, the due date is usually estimated by calculating the date that is 40 weeks from the start of a woman's LMP.

Ultrasound

Estimating due date based on ultrasound involves the use of soundwaves to look inside the body and compare the growth of the fetus to typical growth rates of babies around the world. It is a simple process that can be performed quickly and easily, that has no known risk to babies, and can be an accurate estimate of the due date early in the pregnancy.

Conception date

Using conception date to estimate due date is similar to using the last menstrual period. There is a difference of about two weeks between using these two methods that is based on the timing between the last menstrual period and the date of conception.

In vitro fertilization (IVF)

When using in vitro fertilization, the estimation of the due date is generally more precise than calculating the due date based on natural conception, since the exact transfer date is known. It still uses the average gestational age at birth of 40 weeks from a woman's last menstrual period, as do the other methods. In the case of IVF, however, the due date estimate can be made based on LMP, day of ovulation, egg retrieval, insemination, as well as the date of the 3-day or 5-day embryo transfer. In this calculator, the embryo transfer date is used.

Due date as a reference point

Generally, the point within the 37 to 42-week window at which the baby is born is not a cause for concern. Babies born between 37-39 weeks, 39-41 weeks, and 41-42 weeks are considered early term, full-term, and late-term, respectively. Under normal circumstances, babies born within any of these ranges can be healthy, though full-term babies generally have better outcomes.2 Babies born before 37 weeks are considered preterm, or premature, while those born after 42 weeks are postterm. These ranges are important as a reference for doctors to determine whether or not any action is necessary. For example, if a woman goes into labor too early at 33 weeks, doctors may stop labor to avoid a preterm baby that can have a host of health issues due to underdevelopment. Conversely, if a woman has not gone into labor after 42 weeks, doctors may induce labor. One possible complication of allowing the pregnancy to proceed beyond 42 weeks is that the placenta, which is responsible for providing nutrition and oxygen to the baby, can stop functioning properly, while the baby continues growing (requiring more nutrients and oxygen), which would eventually lead to a point in the pregnancy where the baby can no longer be adequately supported.3

Have you been trying to work out your baby’s due date and found yourself adding, subtracting, multiplying and counting on your fingers? Working out your due date can be confusing, but luckily, our handy pregnancy due date calculator can help you easily find out when your baby might make an appearance based on the first day of your last period.

And we suggest other calculation methods to use, including a due date calculation for IVF pregnancies.

How we calculate your baby’s due date

Even if you've been tracking your ovulation, there's no way to know for sure exactly when you ovulated and conceived. That's why your baby’s due date is often based on the date of your last period instead. Health professionals often call this your LMP, or last menstrual period.

Most women ovulate about two weeks after the first day of their period, and conceive shortly afterwards. The average pregnancy lasts between 37 weeks and 42 weeks. Our pregnancy due date calculator uses this information to give you an estimated due date.

Other ways to calculate your due date

Conception date

If you’ve been using an ovulation predictor kit or tracking your cycle using an app then you may be able to calculate your due date using your conception date. The challenge with this method is that getting your date of conception right can be tricky as you won’t necessarily conceive on the day you have sex.

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. That gives you a six-day window when you might conceive. If you’re pretty sure, then add 38 weeks to your date of conception to work out when your baby may be due.

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.

Will my baby definitely be born on my due date?

Your due date is a best guesstimate, but unfortunately, no one can say for sure exactly when your little one will arrive. In fact, only about four in 100 babies are born on their due date! But it is likely that your baby will arrive in the few weeks either side of your estimated due date. Knowing this can help you to be prepared for labour and birth, and to have everything ready for your new baby.

Will my due date change when I have a scan?

It may do. Your first pregnancy scan will probably happen when you're between 10 weeks and 14 weeks pregnant. It's known as the dating scan, and is used to give you a more accurate due date, based on the size and development of your baby. Learn more about antenatal scans.

When can I take a pregnancy test?

If you’re trying for a baby you’ll probably be keen to take a pregnancy test as soon as possible. Try to be patient, you’ll get a more reliable result if you wait a few days after your missed period before taking a test.

Home pregnancy tests detect the presence of the pregnancy hormone, called human chorionic gonadotrophin (hCG), in your wee. If you test too early, particularly before you've missed a period, there may not be enough hCG in your body for a home pregnancy test to show an accurate reading.

Levels of hCG are typically fairly high at around six to seven weeks of pregnancy. So, by the time your period is a week or two weeks late, you should get a definite result. You might even be showing signs of pregnancy!

What is my due date if I conceived on?

Conception Date: If you have been using an ovulation predictor kit or tracking your ovulation you may be able calculate your due date based on the precise date of conception. In order to do this simply count 266 days, or 38 weeks, from the conception date to find your estimated due date.

How many weeks are you the day you conceive?

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.)

How do you calculate the day you conceived a baby?

When is my conception date? To find your conception date, you will have to perform some calculations to estimate it. Find out on what day your last period began, and add your average cycle length in days to that date. Finally, subtract 14 days and you will have an estimate of conception date.