Find your estimated due date, see how far along you are, and track key milestones week by week.
Enter your last period date to see your due date and pregnancy timeline.
The most common method (Naegele's Rule) adds 280 days (40 weeks) to the first day of your last menstrual period. This assumes a 28-day cycle with ovulation on day 14. Your doctor may adjust based on ultrasound measurements.
Pregnancy is divided into three trimesters. The first trimester is weeks 1-12, the second is weeks 13-26, and the third is weeks 27-40. Each trimester brings different developments and milestones for both baby and mother.
Only about 5% of babies are born on their exact due date. Most births occur within two weeks before or after the due date. A pregnancy is considered full-term at 39-40 weeks and early-term at 37-38 weeks.
Due date calculators based on last menstrual period are accurate to within 1-2 weeks for most women with regular cycles. Early ultrasounds (before 14 weeks) are the most accurate method for dating a pregnancy. Your healthcare provider will confirm and may adjust your due date based on ultrasound measurements.
The first trimester runs from week 1 to the end of week 12. The second trimester runs from week 13 to the end of week 26. The third trimester runs from week 27 until birth, typically around week 40. The second trimester is often called the "honeymoon period" as many early pregnancy symptoms improve.
Home pregnancy tests are most accurate when taken after your missed period. Some sensitive tests can detect pregnancy as early as 10-12 days after conception (before a missed period). For the most accurate result, test in the morning when pregnancy hormone (hCG) levels are highest.
A full-term pregnancy is 39-40 weeks. Early-term is 37-38 weeks, late-term is 41 weeks, and post-term is 42 weeks or beyond. Babies born before 37 weeks are considered premature. Most doctors will discuss induction options if pregnancy extends beyond 41-42 weeks.