Ovulation can be calculated by the following methods: 1. rough estimation: ovulation is about 14 days before the next menstrual period; 2. detailed examination of ovulation: including basal body temperature measurement, if the patient shows elevated basal body temperature, it indicates that the ovaries have ovulated; 3. precise examination: the patient can go to the hospital for ultrasound examination to detect the follicle size, immediate condition and whether it is synchronized with the endometrium. Under the guidance of the doctor, it will further help the patient to understand the follicle development and current status, and provide timely guidance to the patient for conception. Currently, the most commonly used clinical test is basal body temperature measurement, or ultrasound monitoring with urinary LH or blood hormone measurement to clarify the date of ovulation.