Generally after pregnancy, there is a reaction around 6 weeks of menopause. After fertilization there is an increase in the level of some hormones, like maternal estrogen, progesterone, and chorionic gonadotropin. Around 6 weeks after menopause, pregnant women experience morning sickness, nausea, drowsiness, weakness and acid reflux. These reactions are called early pregnancy reactions and are related to the increase of chorionic gonadotropin levels in the body. During 8-9 weeks of pregnancy, the secretion level of chorionic gonadotropin reaches its peak, and during 12 weeks of pregnancy, the level of chorionic gonadotropin starts to decrease, and the mother’s early pregnancy reaction will slowly decrease at that time. Therefore, early pregnancy reaction will occur at about 6-7 weeks of pregnancy. The specific individual situation is different, some people have no reaction, some people have a more violent reaction, also called pregnancy vomiting, and it is necessary to go to the hospital for examination and treatment.