The ovulation phase typically occurs about midway through the menstrual cycle, around day 14 in a standard 28-day cycle. It happens after the follicular phase and before the luteal phase. Ovulation is triggered by a surge in luteinizing hormone (LH) and involves the release of a mature egg from the ovary. This phase usually lasts from 16 to 32 hours and marks the most fertile period of the cycle, occurring roughly 12 to 14 days before the next period begins. The exact timing can vary, with ovulation generally occurring between days 11 and 21 depending on individual cycle length and variation.
More details on the timing of ovulation
- Ovulation follows the follicular phase, which lasts about 10 to 17 days, during which follicles in the ovary mature.
- A peak in estrogen toward the end of the follicular phase triggers the LH surge, which then induces ovulation within about 24 hours.
- The fertile window typically includes a few days before ovulation and the day of ovulation itself, as sperm can survive for up to five days, and the egg remains viable for about 12 to 24 hours after release.
Summary of the menstrual cycle phases relevant to ovulation
- Follicular phase: From the first day of menstruation to ovulation (approximately first 14 days in 28-day cycle).
- Ovulation: Mid-cycle, around day 14 in a 28-day cycle.
- Luteal phase: After ovulation until the start of the next period, about 14 days long.
This means the ovulation phase occurs about two weeks before the start of the next menstrual period, with the peak fertile period spanning a few days around this event.
