It is normal to have no reaction to pregnancy sickness at 8 weeks of pregnancy, which means that the pregnancy reaction is small. After pregnancy, the hormone levels in the pregnant woman’s body will be higher, especially estrogen, progesterone and human chorionic gonadotropin. Elevated levels of estrogen will stimulate the gastrointestinal tract, leading to spasms of the smooth muscles of the gastrointestinal tract, so most people will experience nausea and vomiting. In pregnant women with more severe vomiting, the symptoms will last until 16-18 weeks, but usually most of them may have their symptoms reduced one by one after 12 weeks. Some pregnant women may experience nausea and vomiting throughout their pregnancy due to mental stress, emotional instability, depression, and a weak constitution, which may cause symptoms throughout the pregnancy. However, some pregnant women who are in good physical condition and whose fertilized eggs are more stable will have relatively fewer reactions to pregnancy and may not experience nausea, vomiting and other symptoms. As long as everything is normal during pregnancy and there are no abnormalities in the fetus, it is often a normal phenomenon and there is no need to worry too much. It is recommended that pregnant women should not be overly stressed, and should pay attention to ensuring balanced nutrition in their daily life, eating a light diet rich in high quality protein, high vitamin, easy to digest, as well as fresh fruits and vegetables, and ensuring sufficient sleep to promote the normal development of the fetus.