If the sperm and the egg unite successfully after intercourse and become established, an early pregnancy reaction will occur about ten days after intercourse. However, the symptoms of nausea, vomiting or vomiting are generally inferred by calculating the time of menopause, which usually occurs around 45 days after menopause, and are most obvious in the morning. However, the time of early pregnancy reaction may vary according to individual differences. Some women have better health and will not experience significant discomfort or vomiting after pregnancy. For women with poorer constitution, they may experience nausea and vomiting when the fertilized egg is laid and hormonal changes occur in the body, or in severe cases, they may vomit when they eat. In some cases, the vomiting may even last for the entire pregnancy and require hospitalization.