Mother & Baby
What's your fertile window?
Based on your last period's first day and cycle length
Ovulation happens, on average, 14 days before your next period. Enter the first day of your last period and your usual cycle length, to see your estimated ovulation day and fertile window.
Estimated ovulation day
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Fertile window
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🔒 The data you enter is processed instantly on your device. We don't save or collect anything.
This result is a guideline — real cycles vary, talk to a doctor for precise planning.
Standard calendar method — constant 14-day luteal phase.