The success of pregnancy is not significantly related to whether you have intercourse in the morning or at night on the day of ovulation. The process by which sperm and egg combine to form a fertilized egg is called fertilization. Sperm survives in the female reproductive tract for 48 to 72 hours, and the egg survives for 24 to 48 hours. Fertilization is most often completed a few hours after the egg is released, usually no more than 24 hours. Since the exact time of ovulation cannot be determined, it is not possible to determine whether intercourse in the morning or at night is likely to result in pregnancy. Most women who have regular menstrual periods ovulate about 14 days before their next menstrual period, and it is easy to conceive if you have intercourse 4 to 5 days before or after the day of ovulation. Women regularly monitor ovulation, increase the frequency of coitus during the fertile period, live a regular life and relax, which is conducive to increasing the chances of conception. Women who are preparing for pregnancy should consult a regular hospital to predict the time of ovulation under the guidance of a professional doctor, so as to increase the chances of conception.