In women with regular menstrual cycles of 28-30 days, ovulation occurs about 14 days before the next menstrual period or about 16 days into the period, during which stretched leucorrhea occurs. Ovulation can also be affected by emotions and the environment, resulting in early or delayed ovulation. For women with irregular menstrual cycles who want to know the exact ovulation period to guide their fertility, ovulation can be monitored by ovulation test or pelvic ultrasound, starting from the 10th day of menstruation, and ovulation will occur when the ovulation test changes from strong positive to negative and the pelvic ultrasound follicle diameter is around 2cm. The egg can survive for 24 hours and the sperm can survive for 72 hours. The chances of pregnancy are significantly higher when you have intercourse a few days before and after ovulation. A blood test can be performed 7 days after ovulation to see if conception is successful, so that the development of the embryo can be monitored dynamically to avoid inadvertent miscarriage.