Estimate your most fertile days, your ovulation date and your next few periods from your last period and cycle length.
Ovulation is estimated about 14 days before your next period, and the fertile window covers the five days before ovulation plus the day itself. This assumes a regular cycle and is an estimate only. It must not be used as contraception or to diagnose pregnancy.
It assumes ovulation happens about 14 days before your next period starts. The next period is your last period plus your cycle length, so a longer cycle pushes ovulation later. This is the standard calendar estimate.
It is the days when conception is most likely: the five days leading up to ovulation plus ovulation day itself. Sperm can survive several days, which is why the window starts before ovulation.
No. Calendar estimates are approximate and cycles vary month to month, so this tool must not be used as contraception or to diagnose pregnancy. For those, use a medical method or speak to a healthcare professional.