I have my period on the 21st, which day is ovulation?

- Calculation cycle: Calculated from the first day of the last menstrual period, every 7 days is a cycle. If the cycle is 28 days, then the calculation starts on the 2nd and ends on the 10th.

- Use the David Calendar: The David Calendar is a popular calculation method that helps women predict their ovulation days. Each date on the David calendar represents a different number of days, making it easier to understand your cycle and ovulation.

Regardless of which method you use, you should remember that everyone's cycle is different, so the exact day of ovulation cannot be determined. If you are unsure, it is best to seek advice from your doctor or other professional.