The day after the day of ovulation, which is the period of ovulation, there is a chance of pregnancy, but the chances vary from person to person. The chances of pregnancy increase to about 90% when you have intercourse during ovulation. Currently, the luteinizing hormone in the urine can be checked by ovulation test, which will peak 24-48 hours before ovulation, showing 2 red bars of the same color, indicating the time of ovulation. In women who usually have regular menstrual cycles of 28-30 days, ovulation usually occurs about 14 days before the next menstrual period. During ovulation, vaginal discharge increases significantly and is clear and egg-white like and can be stretched. Ovulation can occur within 24h of the appearance of this discharge. Alternatively, ultrasound monitoring is the most accurate method to observe the size, number and shape of the follicles and the state of the endometrium, which is usually expelled when the follicles reach 18-25mm in diameter. Ultrasound monitoring is relatively the most expensive but also the most accurate.