Most women can experience a reduction in pregnancy vomiting at nine weeks of pregnancy. The vomiting that occurs after a woman becomes pregnant is mainly related to the level of HCG after a woman becomes pregnant. Most vomiting starts around 35-40 days of pregnancy and gradually increases with the rise of HCG. At around nine weeks of pregnancy, the levels of HCG and progesterone will reach their peak and gradually stabilize. Therefore, pregnancy vomiting will reach its peak and then stabilize and gradually appear to decrease. Around the third month of pregnancy, most women’s pregnancy vomiting will gradually decrease and disappear. Some women may experience a decrease in vomiting around the ninth week of pregnancy, especially if the vomiting disappears suddenly, so that the possibility of embryonic arrest should be ruled out. The reason is that after the embryo stops developing, the HCG and progesterone levels of the pregnant woman drop and the pregnancy vomiting can disappear.