Calculation of ovulation can be done through menstrual cycle projection, measurement of basal body temperature, observation of cervical mucus, ultrasound monitoring and so on. 1. Calculation of menstrual cycle: the first day of the next menstrual period is 14 days ahead of the day of ovulation, and the days before and after the day of ovulation are the period of ovulation, which is not applicable to every woman, but is more suitable for those who have regular menstrual periods and a regular life. 2. Measurement of basal body temperature: you can measure the body temperature when you wake up in the morning. Generally, the body temperature is lower in the first half of the menstrual period, and it will be even lower when you reach the ovulation period, and it will rise gradually after the ovulation period, and you can observe it through the temperature change. 3. Observation of cervical mucus: when approaching the ovulation period, the mucus will become clear, smooth and elastic, like egg white, with the degree of pulling to the degree that it is not easy to pull off, generally the last day of the appearance of this mucus and 48 hours before and after the last day of the day is the day of ovulation. 4. Ultrasound test: you can go to the regular hospital by the doctor through the ultrasound observation of follicle development to judge, is a more accurate method.