Ovulation is an important indication of a woman’s fertility. Usually, a normal woman will ovulate once a month, with only 1-2 eggs being ovulated at a time. In women with regular periods, ovulation usually occurs about 14 days before the next menstrual period, during which a woman has a higher chance of conceiving. In the case of irregular menstruation, the time of ovulation cannot be determined. In addition, ovulation is affected by many factors, such as physical, emotional and internal and external environment, so it is difficult to predict ovulation accurately. The methods commonly used in clinical practice to predict ovulation include: 1. Basal body temperature measurement: Generally, the body temperature will rise by 0.3℃-0.5℃ at the time of ovulation and continue until 1-2 days before menstruation or the first day of menstruation, when the body temperature drops back to the original level. The measurement must be done with a normal routine, the daily sleep time should be kept above 6 hours, and the measurement time should be approximately the same every day; 2. Method of calculating the date of menstruation: the first day of ovulation = the shortest menstrual cycle days minus 18 days; the last day of ovulation = the longest menstrual cycle days minus 11 days. If you have irregular menstrual periods, you cannot use this method; 3. Ultrasound detection method: If you have the conditions, you can go to the hospital to detect the maturity of the follicles through ultrasound. If the day of observation falls on the day of ovulation, sometimes you can even see the follicle rupture on the ultrasound.