First day of last period

Well-nigh pregnancies terminal around twoscore weeks (or 38 weeks from conception), and so typically the best way to guess your due appointment is to count 40 weeks, or 280 days, from the first day of your terminal menstrual period (LMP). You could besides subtract three months from the first day of your final menstruum and add seven days.

The first day of your LMP is how virtually health intendance providers estimate a baby's due date. Only remember, it's only an estimated due date, not a deadline for your baby to make it. Simply 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 test strips, then you may exist able to use your conception date to summate your pregnancy due engagement. Simply add 266 days to get your estimated due date (or select "Formulation Date" from the menu to a higher place, and let our Due Date Reckoner do the math for you).

IVF transfer date

If yous conceived through in vitro fertilization (IVF), you can calculate your due engagement using your IVF transfer date. Most embryo transfers occur either 3 days or five days afterwards egg retrieval and fertilization. If you had a day-three transfer, count 263 days from the transfer date to calculate your due date, and if you had a day-5 transfer, count 261 days. (Or select "IVF" from the menu higher up.)

Ultrasound scan

Even if you can't pinpoint when you conceived, forget the solar day of your terminal menstrual flow or aren't sure when ovulation occurred, other clues can assistance you and your practitioner determine your due engagement at your first prenatal date, including:

  • An early ultrasound, which can more accurately date the pregnancy. Just exist aware, yet, that not all women become an early ultrasound. Some practitioners perform them routinely, merely others simply recommend one if your periods are irregular, you're 35 or older, y'all have a history of miscarriages or pregnancy complications, or the due date can't be adamant based on your physical exam and LMP.

  • Pregnancy milestones such as the first time the baby'south heartbeat is heard (around week 9 or 10, though it tin vary) and when yous beginning feel fetal motion (on average betwixt 18 and 22 weeks, but information technology tin can be earlier or later), can requite clues as to whether your due date is accurate.

  • Your fundal meridian, which is the measurement from your pubic os to the top of your uterus, is checked past your practitioner at each prenatal visit and helps confirm your due appointment.

  • The size of your uterus, which will exist noted when your initial internal pregnancy exam is performed, can too exist a cistron in pinpointing the EDD.

Can I plan my due date?

Whether yous're trying to avoid being very pregnant in the middle of summer or are a teacher who wants to maximize time off with your little ane, you tin effort to time when you lot conceive in order to "plan" your due date. Just even if y'all're one of the lucky ones who'southward able to get meaning when she really wants to, only remember that y'all probably won't be able to map out exactly when you'll give birth to the 24-hour interval (or even the week or month!).

Still, you tin effort our Ovulation Computer, which uses the date of your last menstrual catamenia and your typical cycle length to discover the days you're most likely to be fertile and increase your chances of conceiving.

Tin my due date change?

Yep, your due date tin can change. While it's definitely non a reason to worry, your md may modify your due date for a number of reasons every bit your pregnancy progresses.

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

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