Usually, the time it takes for the sperm and egg to combine is usually around 24 hours, but the exact time varies from person to person. After intercourse, the sperm travels towards the uterus with a tail swing, then into the fallopian tubes and reaches its final destination, the juxtaposition of the fallopian tubes, where it waits to unite with the egg. The fusion of the chromosomes of the sperm and the egg indicates the completion of the fertilization process, after which the fertilized egg gradually moves towards the uterine cavity and deposits itself in the endometrium. Fertilization usually occurs about 12 hours after ovulation and the entire process takes about 24 hours. The process of fertilization may be affected by tubal incompatibility, insufficient secretion of sex hormones, etc., which may also prolong the time of fertilization, or fertilization may fail. In addition, patients are advised to go to the hospital for a checkup to determine whether the sperm and egg have combined properly and have implanted in the uterus.