When the sperm and egg unite and a fertilized egg is formed, the body’s reactions to successful implantation and conception include implantation pain, vaginal bleeding, breast swelling and pain, weakness, drowsiness, food loss, and changes in taste. When a fertilized egg is implanted, the fertilized egg invades the endometrium, causing the endometrium to rupture, which is prone to implantation pain, mild vaginal bleeding or bloody leucorrhea. After the formation of the fertilized egg, the level of estrogen and progesterone in the body increases, making it easy to experience breast swelling and pain. During early pregnancy, due to changes in the hormone level in the body, it is easy to experience drowsiness and fatigue. The increased estrogen stimulates the hypothalamic nerve center and reflexively causes gastrointestinal reactions, making it easy to experience nausea, vomiting, food loss, and acidity. Once the sperm and egg unite to form a fertilized egg, the body will experience different degrees of early pregnancy reactions, which are mainly influenced by the hormone levels in the body.