Fertilization of the egg takes place in about 24 hours. Once the male sperm enters the female vagina, it relies on the tail to swing forward, and by releasing proteolytic enzymes, it dissolves the cervical mucus, reaches the fallopian tube jugular and unites with the egg, is energized and enters the zona pellucida of the egg cell, which indicates the start of fertilization. The fertilization process is complete if the chromosomes of the sperm and egg are normally joined together, which takes about 24 hours. The formation of a fertilized egg means the beginning of pregnancy, but not the success of the pregnancy. It takes 3-4 days after fertilization to move into the uterine cavity, about 7 days for implantation, and 10 days for implantation to end and for the embryo to grow and develop normally. For women who are planning to have children, they can use their menstrual cycle to project the ovulation period. Having intercourse around the time of ovulation can increase the chances of pregnancy, and avoid washing the vagina immediately after intercourse so that the sperm can stay in the vagina for a longer time.