After intercourse, it takes about 7 days for the fertilized egg to settle. If intercourse happens around the time of ovulation, the egg and sperm will meet after intercourse to form a fertilized egg, which will arrive in the uterine cavity and begin to implant around the 5th-7th day after ovulation. Since the time of ovulation is not completely fixed, the formation of the fertilized egg after intercourse is not completely certain, and it is common to postpone it by 1-2 days. However, in most women, the pregnancy process is not obvious at the time of fertilized egg implantation. Only a small number of women may experience pain and discomfort in the lower abdomen and lumbosacral area, or even a small amount of bloody discharge at the time of fertilization. Failure of fertilization may occur if the fertilized egg is stimulated by harmful factors such as viral infection, medication or radioactive damage during the process of fertilization.