Frequently asked questions
How accurate is a due date?
Only about 1 baby in 20 arrives on the day itself. Most come within two weeks either side, so think of it as the middle of a window.
Do I count from my last period or from conception?
From the first day of your last period, about two weeks before conception. That's why you're already counted as two weeks pregnant when you conceive.
Can a scan change my due date?
Yes. An early ultrasound, especially in the first trimester, is often more accurate than period dates, and your doctor may move the date to match it.
How do I find my fertile days?
Ovulation usually happens about 14 days before your next period, and you're most fertile in the five days before it and on the day itself. The ovulation calculator works it out from your cycle.
Is this medical advice?
No, these are estimates to help you plan. Your doctor or midwife should guide any decisions about your pregnancy.
Is anything I enter sent or stored?
No. Every calculation runs in your browser, and nothing you type is sent to us or saved.