The average time for the sperm to enter the uterus and reach the fallopian tube is about 6 hours at the longest and 1.5 hours at the shortest. Once the sperm enters the fallopian tube, the two will unite to form a fertilized egg, which will then peristaltically move into the uterine cavity and grow and develop into a pregnancy. If you plan to get pregnant, don’t stand up immediately after intercourse to wash your vulva, it’s best to lie in bed and rest for more than an hour to help the sperm enter the uterus faster, if you stand up immediately, it may lead to the possibility of infertility.