First twenty-four hour period of last menses

Virtually pregnancies last around forty weeks (or 38 weeks from conception), so typically the all-time way to estimate your due date is to count 40 weeks, or 280 days, from the beginning day of your last menstrual catamenia (LMP). Yous could as well subtract three months from the commencement day of your final period and add together seven days.

The offset mean solar day of your LMP is how most wellness intendance providers estimate a baby's due engagement. But retrieve, it'southward but an estimated due date, not a deadline for your baby to arrive. Just 4 percent of babies are born on their estimated due date.

Formulation date

If you've been tracking ovulation symptoms or take been using ovulation exam strips, then y'all may be able to use your formulation date to calculate your pregnancy due date. But add together 266 days to get your estimated due engagement (or select "Conception Date" from the menu above, and let our Due Engagement Calculator do the math for you lot).

IVF transfer date

If you conceived through in vitro fertilization (IVF), y'all can calculate your due date using your IVF transfer date. Most embryo transfers occur either three days or five days afterwards egg retrieval and fertilization. If you had a 24-hour interval-3 transfer, count 263 days from the transfer engagement to calculate your due appointment, and if you had a 24-hour interval-five transfer, count 261 days. (Or select "IVF" from the menu higher up.)

Ultrasound browse

Even if you tin can't pinpoint when you conceived, forget the solar day of your last menstrual period or aren't sure when ovulation occurred, other clues can assist you and your practitioner decide your due engagement at your first prenatal appointment, including:

  • An early ultrasound, which can more than accurately engagement the pregnancy. Just be aware, nonetheless, that not all women get an early on ultrasound. Some practitioners perform them routinely, but others only recommend one if your periods are irregular, yous're 35 or older, yous have a history of miscarriages or pregnancy complications, or the due engagement can't be determined based on your concrete exam and LMP.

  • Pregnancy milestones such as the first time the baby'southward heartbeat is heard (around week ix or 10, though it tin can vary) and when you first experience fetal move (on average between 18 and 22 weeks, but information technology can be earlier or later), can give clues as to whether your due appointment is accurate.

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

  • The size of your uterus, which volition exist noted when your initial internal pregnancy test is performed, can likewise be a gene in pinpointing the EDD.

Tin I programme my due date?

Whether you're trying to avoid existence very pregnant in the middle of summer or are a instructor who wants to maximize fourth dimension off with your little one, you tin try to time when you conceive in lodge to "programme" your due date. But even if you're 1 of the lucky ones who'southward able to become pregnant when she actually wants to, just call up that you probably won't be able to map out exactly when you'll requite birth to the twenty-four hour period (or even the week or month!).

Still, you can effort our Ovulation Figurer, which uses the date of your concluding menstrual period and your typical cycle length to discover the days you're most probable to exist fertile and increase your chances of conceiving.

Can my due date alter?

Yes, your due date can change. While it's definitely not a reason to worry, your doctor may change your due date for a number of reasons as your pregnancy progresses.

It may be that you have irregular periods and your early on ultrasound dating was off, or that your first ultrasound was in the 2d trimester.

It could too be considering your fundal height is abnormal, or your levels of alpha-fetoprotein (AFP), a protein made past the baby, are exterior the usual range. Talk to your practitioner if you lot have any questions or concerns.