Understanding your fertile window

If you're trying to conceive, understanding your fertile window can help you time things well.

What is the fertile window?

Your fertile window is roughly the six days ending on the day you ovulate. That's because sperm can survive for up to about five days, and the egg for around a day after it's released.

Estimating ovulation

Ovulation usually happens about 14 days before your next period. So on a 28-day cycle, that's around day 14 — but cycles vary, and so does ovulation.

Our ovulation calculator can give you an estimate from your last period and cycle length. It's a guide only, not a guarantee — and never a form of contraception.