Ovulation typically occurs about 12 to 16 days before the start of your next period. The day you ovulate depends on the length of your menstrual cycle, which is counted from the first day of your period to the day before your next period begins. Here are important points for understanding when you ovulate:
- The average menstrual cycle length is about 28 days, with periods lasting on average from 2 to 7 days.
- In a 28-day cycle, ovulation usually happens around day 14 (about 12 to 14 days after the first day of your period).
- For cycles shorter or longer than 28 days, ovulation shifts accordingly: it generally occurs about 12 to 16 days before the start of your next period. For example, if your cycle is 26-28 days, ovulation is around days 12 to 14.
- The luteal phase (from ovulation to the next period) tends to be fairly consistent, about 10 to 16 days.
- Your fertile window includes the days leading up to ovulation because sperm can survive inside the body for up to 5 days, and the egg is viable for about 12 to 24 hours after release.
To determine your ovulation day:
- Know your average cycle length (days from the first day of your period to the day before your next).
- Subtract 12 to 16 days from that length to find the estimated ovulation day.
If your period lasts several days, ovulation typically occurs about 12 to 16 days after the start of your period depending on your cycle length, not counting the duration of the period itself. For example, if your cycle is 28 days and your period lasts 5 days, ovulation would be approximately on day 14, which is roughly 9 days after your period ends. Thus, the key factor to estimate ovulation is your full menstrual cycle length, not just how many days your period lasts.
