Offset day of last flow

Most pregnancies last around 40 weeks (or 38 weeks from formulation), so typically the best way to estimate your due date is to count 40 weeks, or 280 days, from the first twenty-four hours of your last menstrual menses (LMP). You could also subtract iii months from the kickoff twenty-four hours of your last period and add 7 days.

The first day of your LMP is how most health care providers estimate a baby's due engagement. But remember, information technology's only an estimated due appointment, not a deadline for your babe to get in. Just 4 percent of babies are built-in on their estimated due date.

Conception date

If y'all've been tracking ovulation symptoms or accept been using ovulation test strips, then you may be able to use your conception date to summate your pregnancy due date. Just add together 266 days to get your estimated due date (or select "Conception Appointment" from the card above, and let our Due Date Estimator do the math for y'all).

IVF transfer engagement

If yous conceived through in vitro fertilization (IVF), you tin calculate your due date using your IVF transfer appointment. Most embryo transfers occur either three days or five days after egg retrieval and fertilization. If you had a day-iii transfer, count 263 days from the transfer date to calculate your due appointment, and if you had a day-five transfer, count 261 days. (Or select "IVF" from the bill of fare above.)

Ultrasound browse

Even if you can't pinpoint when y'all conceived, forget the twenty-four hour period of your terminal menstrual period or aren't certain when ovulation occurred, other clues tin can aid you and your practitioner decide your due date at your outset prenatal appointment, including:

  • An early ultrasound, which can more accurately date the pregnancy. Just be enlightened, all the same, that non all women become an early ultrasound. Some practitioners perform them routinely, but others only recommend one if your periods are irregular, you're 35 or older, you have a history of miscarriages or pregnancy complications, or the due date tin't be determined based on your concrete examination and LMP.

  • Pregnancy milestones such every bit the first fourth dimension the baby'southward heartbeat is heard (effectually week 9 or 10, though it can vary) and when you outset feel fetal movement (on boilerplate between 18 and 22 weeks, but information technology can exist before or afterwards), can give clues as to whether your due engagement is accurate.

  • Your fundal top, which is the measurement from your pubic os to the summit of your uterus, is checked by your practitioner at each prenatal visit and helps ostend your due date.

  • The size of your uterus, which will be noted when your initial internal pregnancy exam is performed, tin can also be a factor in pinpointing the EDD.

Can I plan my due date?

Whether you're trying to avoid existence very pregnant in the middle of summer or are a teacher who wants to maximize time off with your little one, you can try to time when you lot conceive in order to "plan" your due engagement. But even if yous're one of the lucky ones who's able to become pregnant when she really wants to, just remember that you lot probably won't be able to map out exactly when yous'll give birth to the twenty-four hours (or even the week or month!).

Still, you lot can try our Ovulation Estimator, which uses the appointment of your last menstrual catamenia and your typical cycle length to observe the days y'all're most likely to be fertile and increase your chances of conceiving.

Can my due date change?

Yes, your due date tin change. While information technology's definitely not a reason to worry, your medico may change your due date for a number of reasons as your pregnancy progresses.

It may be that yous have irregular periods and your early ultrasound dating was off, or that your first ultrasound was in the second trimester.

It could also be because your fundal height is abnormal, or your levels of alpha-fetoprotein (AFP), a protein made by the baby, are outside the usual range. Talk to your practitioner if you lot take whatever questions or concerns.