In women with very normal periods, early pregnancy reactions such as nausea and vomiting will start to appear around 40 days of pregnancy. In women with delayed menstruation, the onset of pregnancy vomiting will be delayed accordingly, usually around 45-50 days at the latest. During early pregnancy, the increase in chorionic gonadotropin level and the prolonged gastric emptying time in pregnant women will lead to nausea and vomiting and other early pregnancy reactions. Early pregnancy reactions are affected by the pregnant woman’s sleep, diet and emotions, and the symptoms and reactions vary. The occurrence of pregnancy vomiting and the fluctuation of chorionic gonadotropin level also have a great relationship, so about two months after menopause is usually a relatively serious stage of early pregnancy reaction, and around 12 weeks, as the hormone level gradually stabilizes, the pregnancy vomiting reaction will gradually disappear. After the occurrence of pregnancy vomiting reaction, it is required to maintain sufficient sleep and rest, relax, and have a healthy and balanced light diet, which is conducive to the improvement of early pregnancy reaction.