Ovulation typically starts about 11 to 21 days after the first day of menstruation, depending on the length of the menstrual cycle. In an average 28-day cycle, ovulation generally occurs around day 14, which corresponds to about 10 to 14 days after menstruation begins. This means ovulation usually happens about 14 days before the next period starts. If the cycle is shorter or longer, ovulation can happen earlier or later accordingly. Key points:

• Ovulation usually occurs around the midpoint of the menstrual cycle, after the menstrual phase and follicular phase.
• For a 28-day cycle, ovulation is around day 14, roughly 10 to 14 days after menstruation begins.
• The fertile window is a few days before and the day of ovulation.
• Ovulation timing varies widely among individuals and cycles.

This timing reflects the average, with actual timing influenced by individual cycle length and regularity. The hormone surge (luteinizing hormone) triggers ovulation, which lasts about 16 to 32 hours. After ovulation, if the egg is not fertilized, menstruation begins about 14 days later.