For a woman whose period is on the 10th, if her menstrual cycle is regular and 28 days long, the ovarian ovulation should be on the 24th of the month. However, if a woman’s menstrual cycle is regular but not 28 days, she should first calculate the exact date of her next menstrual period, and then push back 14 days after calculating the corresponding date, which is the exact date of ovulation. However, if a woman has an irregular menstrual cycle, it is impossible to calculate the exact date of the next menstrual period. If you want to know the exact day of ovulation, you can perform ultrasound to monitor the follicular development and predict the day of ovulation.