If a woman usually has a regular menstrual cycle, she will ovulate once a month, and the day of ovulation is usually about 14 days before her next period. The duration of ovulation is usually relatively short and may be only a few hours. The egg can survive 1-2 days after ovulation and the sperm can survive 2-3 days in the female reproductive tract, so it is easy to conceive when having intercourse during the days before and after the egg is expelled. Therefore, the period of 10 days, including the 5 days before or 4 days after the day of ovulation, is generally referred to as the ovulation period. For women with irregular periods, ovulation can be monitored by ovulation test strips or by ultrasound at the hospital, usually every other day, until ovulation is detected. In addition, you can also determine the time of ovulation by taking the basal body temperature. To monitor the basal body temperature, you can put the thermometer on your bed before going to bed at night, and then go to take the temperature in the morning without washing or moving around, and record it. In the menstrual cycle, the basal body temperature before ovulation is slightly low, and after ovulation the basal body temperature will rise slightly by about 0.3℃-0.6℃ and will be maintained until the next menstruation. Therefore, if you find a mild increase in body temperature, you are ovulating. If you are planning to get pregnant, you can have intercourse once every other day during the ovulation period so that the chance of conception will be higher. If you are not planning to get pregnant, because of the possibility of accidental ovulation, it is recommended that you take birth control measures in advance and do not use a safe period.