Cycle health

Your fertile window, explained — and how to actually find it

There are only about six days each cycle when pregnancy is possible. Here is the science of timing them — without the guesswork.

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Reviewed by the Lalu medical team · July 1, 2026 · 1 min read

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Across a whole cycle, there are only about six days when pregnancy is actually possible. Find them, and everything else gets simpler.

What the fertile window actually is

It is defined by how long sperm survive and how long an egg lives after ovulation.

Ovulation is a single day. Fertility is a window.

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Lalu medical reviewer

Part of the Lalu clinical team that writes and reviews our cycle, pregnancy and baby content.

Lalu turns this guidance into a plan that fits your body, your week, your baby.