The time between intercourse and pregnancy is usually 7-8 days. A woman conceives within 15-18 hours after the egg is discharged from the ovary, and the egg usually survives in the body for two days after discharge. After intercourse, the active sperm in the semen passes through the uterus to the abdomen of the fallopian tube to meet and fertilize the egg, and after fertilization, the fertilized egg is sent back to the uterine cavity by the peristaltic movement of the fallopian tube. After fertilization, the fertilized egg is returned to the uterine cavity by the peristaltic movement of the fallopian tube. After 2-3 days of traveling in the uterine cavity, the egg will find a suitable embryonic site and will grow and develop into an embryo in the uterine cavity, so it takes about 7-8 days. If ovulation occurs during intercourse, the sperm and egg may unite in about 2 hours, and the fertilized egg will successfully conceive after it has been laid. However, if there is no ovulation at the time of intercourse, the sperm will live in the body for about 72 hours, so if ovulation occurs within these 3 days, pregnancy may also occur, so the time between intercourse and pregnancy varies greatly from person to person. Women who want to have children can try to have sex before and after ovulation to increase the probability of conceiving and avoid douching before and after sex.