Understanding the Menstrual Cycle and How to Recognize Your Fertile Window

The menstrual cycle is counted from the first day of your period until the day before your next period. In most adult women, a cycle lasts between 21 and 35 days, with bleeding lasting about two to seven days. Slight variations from month to month are still considered normal.

The fertile window is the time when the chance of pregnancy is highest, which is from a few days before until one day after ovulation. In a 28-day cycle, ovulation usually occurs around day 14. Signs you can observe include cervical mucus that becomes clearer and stretchier, as well as a slight rise in basal body temperature.

Tracking your cycle regularly, whether in a notebook or an app, can help you recognize your body’s patterns. However, calculating the fertile window is not always accurate, especially if your cycles are irregular, so it is not recommended as your only method of preventing pregnancy.

See an obstetrician-gynecologist if your periods are very irregular, very heavy, very painful, or have stopped for several months without a clear reason.