How to calculate ovulation on day 28 of the cycle?

The egg in the female cycle starts on the 14th day of each month and lasts for about 4-5 days. Therefore, if a woman's cycle is 28 days, then the 5 days starting from the 14th day are the women's ovulation period.

Of course, this is just a basic calculation method. The length and regularity of a woman's menstrual cycle may vary, so the exact calculation method may vary for different women.

Women can calculate their ovulation by:

1. Observe your own sexual desire: Women’s sexual desire may increase during ovulation, so you can judge your ovulation period by observing your own sexual desire.

2. Measure body temperature: Women can determine their ovulation period by measuring body temperature. Typically, a woman's body temperature will rise by 0.3-0.5 degrees Celsius during ovulation.

3. Watch for symptoms: Some women may experience symptoms during ovulation, such as breast swelling, abdominal pain, and headaches.

To sum up, calculating a woman’s ovulation period needs to be based on her own cycle and symptoms. If a woman is unsure about her cycle or symptoms, it is recommended to consult a doctor or professional health advisor.