Pregnancy weeks to months
How many months pregnant am I?
You can use the chart above to figure out how the weeks of pregnancy correspond to months. Note that you're not technically one month pregnant until after 4 weeks have passed, for example. But you are "in your first month" during the first 4 weeks and "in month nine" during the last 4 weeks
Isn't a month four weeks long?
Actually, in a typical year, February is the only month that's four weeks (or 28 days) long. All others are either 30 or 31 days. On average, a month is 4.3 weeks, so that means the number of weeks and months of pregnancy don't match up exactly. And that's why some months in the chart are four weeks long and some are five weeks long
Is pregnancy nine or ten months?
Forty weeks is actually a little more than 9 months. For example, if your last period started on January 1, your due date would be October 8. So that's more like nine months and one week (or even longer if you go past your due date)
How long is each trimester?
There's no official definition, but each trimester is generally considered to be about three months long. At BabyCenter, you reach the second trimester the day you turn 14 weeks pregnant. The third starts the day you turn 28 weeks pregnant.
Why is my pregnancy counted from my last period?
Because it's the easiest date to pinpoint. Many women don't know the day they ovulated. So doctors and midwives start counting pregnancy from the first day of your last menstrual period (LMP), which is usually about two weeks before you ovulate
(By the way, even if you know the day you had sex that resulted in pregnancy, that may not be the day you conceived: Sperm can linger in your uterus for up to five days waiting for an egg to be released so they can fertilize it.)
How is my due date calculated?
Your provider counts 280 days (40 weeks) from the first day of your LMP to determine your due date. But keep in mind that's just an estimate. Only 5 percent of babies are born on their due date. You're just as likely to deliver any time during the two weeks before or after that day. Your baby is considered full term between 39 and 41 weeks