Ovulation can be estimated under the guidance of a doctor through the calendar method, basal body temperature measurement, cervical mucus observation and ultrasound monitoring. 1. Calendar method: It is mainly applicable to women with regular menstrual cycles. Since ovulation occurs about 14 days before the next menstrual period, the day of ovulation can be deduced from the calendar recording of the menstrual cycle time, plus 4-5 days before and after the ovulation is the ovulation period. 2. Basal Body Temperature Measurement: As the level of progesterone rises after ovulation, the basal body temperature will rise by 0.3℃~0.5℃, so you can start monitoring and recording the temperature from the first day of menstruation until the temperature rises to indicate ovulation, and it is recommended that you choose the same time every day and measure the temperature in a quiet state. 3. Cervical mucus observation method: affected by the level of estrogen and progesterone in the body, cervical mucus secretion increases before ovulation, is thin, transparent, and the degree of pulling can reach more than 10cm, while the mucus secretion gradually decreases after ovulation, and becomes viscous and turbid, easy to fracture, can be observed through the changes in the cervical mucus can be projected to the period of ovulation. 4. Ultrasound monitoring: ultrasound is used to monitor the size of follicles from the 10th day of the menstrual cycle until the follicle grows to about 20mm, and most of them will ovulate in about 24~48 hours, which can also be used to predict the ovulation period.