Even if you can’t pinpoint when you conceived, forget the day of your last menstrual period or aren’t sure when ovulation occurred, other clues can help you and your practitioner determine your due date at your first prenatal appointment, including: Whether you'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 one, you can try to time when you conceive in order to "plan" your due date. 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.
But even if you're one of the lucky ones who's able to get pregnant when she really wants to, just remember that you probably won't be able to map out exactly when you'll give birth to the day (or even the week or month! It may be that your periods are irregular and your early ultrasound dating was off, or that your first ultrasound was in the second trimester.
Dating pregnancy by ultrasound
How far along am I, a question asked frequently by pregnant mothers, refers to the amount of time that has elapsed since the start of a woman's last menstrual period (LMP).
Pregnancy is normally counted from a woman's last menstrual period which is about two weeks before baby is actually conceived.
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 have any questions or concerns.
Calculating your due date based on the first day of your last period works well for women who have a relatively regular menstrual cycle.
But if your cycle is irregular, the LMP method may not work for you.
The start of a period is easily observable and usually known to a woman whereas the date of conception is much less likely to be known.
Historically, the first day of the last menstrual period (LMP) became the date from which pregnancy is counted even though conception occurs about two weeks later.
This is how your doctor will estimate your due date — and it’s a pretty solid target.
But remember: It’s just as normal to deliver a week or two before or after.
Our how far along am I calculator uses your due date or last period to calculate how many weeks, months, and days you are pregnant.