Track how far along you are, your progress toward 40 weeks, and how many days are left.
Estimates only, not medical advice.
Every number on this page starts from one date: the first day of your last menstrual period. Pregnancy is dated this way rather than from conception because that date is usually known precisely, while the exact day an egg was fertilized almost never is. From that starting point, a full-term pregnancy runs about 280 days, roughly 40 weeks, to an estimated due date.
The bar above your results is the same 280 day span expressed as a percentage. It grows a little each day and tops out at 100 percent around your due date, though real births cluster in a range rather than landing on a single day. Early in pregnancy the bar will look nearly empty even though a great deal of development is already underway; percentage of time elapsed is a calendar measure, not a measure of how much is happening.
How far along, trimester, due date, and days remaining all come from the same underlying arithmetic once you enter your last period date and average cycle length. If your cycle runs longer or shorter than 28 days, the due date shifts accordingly, and every other figure on this page moves with it. That is also why a different pregnancy app can show a slightly different week count: some default to conception based dating, which lands about two weeks earlier in the count than LMP based dating for the same pregnancy.
| Milestone | Approximate week |
|---|---|
| End of first trimester | Week 13 |
| End of second trimester | Week 27 |
| Early term begins | Week 37 |
| Full term begins | Week 39 |
These figures are estimates for general tracking. Your provider's dating, especially after an early ultrasound, is the one that governs your actual care.
It is the share of a standard 280 day pregnancy that has passed since the first day of your last period, capped at 100 percent.
Different tools sometimes use conception based dating instead of LMP based dating, which shifts the count by roughly two weeks. Confirm which convention your provider uses.
It recalculates from today's date each time you open the page, counting down toward the estimated 40 week due date.
The days remaining figure will show that your estimated date has passed. Going past 40 weeks is common, and your provider will discuss monitoring and next steps with you.