Currently, there are two main methods to monitor ovulation: First, ovulation testing by ovulation test strips sold in the market. The principle of ovulation test strip monitoring is determined by the appearance of LH peak in the body, which is shown as positive or negative on the ovulation test strip. When the LH peak appears, it will indicate that ovulation has occurred in the ovaries in the near future. Therefore, ovulation test strips can be used to monitor whether ovulation has occurred, but whether there are normal follicles in the ovaries and the size of the follicles cannot be monitored, which needs to be further confirmed by ultrasound. Second, ultrasound monitoring of ovulation. Ultrasound monitoring of ovulation is performed from the eighth or tenth day of menstruation. When the follicles are shown to be developing under the ultrasound, a second follicle monitoring can be performed at an interval of 1-2 days until the follicles are mature and successfully expelled under the ultrasound, so this is a more effective process and method to monitor the follicles.