It is normal to have no reaction to pregnancy vomiting, and this is subject to individual differences.
Early pregnancy due to the rise in hormone levels in the body, most pregnant women will be around 6 weeks of pregnancy nausea, vomiting and anorexia and other progesterone response, usually around 12 weeks of pregnancy will disappear on their own, but there are a small number of pregnant women will have no reaction to vomiting, when progesterone and blood HCG (human chorionic gonadotropin) levels are normal, but also a normal physiological phenomenon.
Early pregnancy, whether detected by blood HCG or early pregnancy test paper, must be done at about 6 weeks of pregnancy ultrasound to confirm normal intrauterine pregnancy, but also to rule out the risk of ectopic pregnancy and other pathological pregnancy. When it is clear that early pregnancy should pay attention to appropriate rest, mild pregnancy vomiting reaction will gradually disappear with the increase of pregnancy weeks, while severe pregnancy vomiting need to be hospitalized for rehydration therapy if necessary.