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When you ovulate, when your baby is due and when to test

Three short questions and you will see the answer. Everything is calculated in your browser; nothing is sent anywhere.

What would you like to know?

This is an estimate. Ovulation can shift even with a regular cycle, so calendar calculation is not a method of contraception. A due date based on your last period is confirmed by an ultrasound in the first trimester. If your cycle is irregular, see a doctor — we will find out why.

FAQ
How do I calculate my ovulation day?

Ovulation usually happens about 14 days before your next period. With a 28-day cycle that is around day 14, with a 32-day cycle around day 18.

Which days are most fertile?

The five days before ovulation and the day of ovulation. Sperm can live in the female body for up to 5 days, the egg for about one day.

How is the due date calculated?

280 days (40 weeks) are added to the first day of your last period, adjusted for your cycle length. An ultrasound in the first trimester gives a more accurate date.

When should I take a pregnancy test?

Most reliably from the first day of a missed period, in the morning. If the test is negative and your period still has not come, repeat it in 2–3 days.

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