A clinical distinction is made between the safe and ovulatory periods, mainly because of the problem of the patient’s chances of ovulating during these two periods. Women have the highest chance of ovulating during the ovulation period and a very low chance of ovulating during the safety period. Therefore, the main purpose of calculating the safe period and ovulation period is to help the patient to prevent pregnancy or to help the patient to prepare for pregnancy. Women who are trying to conceive should try to have intercourse during ovulation to greatly improve their chances of conception. For women without fertility requirements, try to have intercourse during the safe period, and if you have intercourse during ovulation, you must do a good job of contraception. As ovulation is affected by many factors, women may also ovulate during the safe period. So for women who do not need to have children, it is important to have good contraception at all times and to use it throughout.