Progesterone does not increase at the same value every day. Serum progesterone levels rise steadily with the increase of pregnancy time, 30-130nmol/L in early pregnancy, 62-260nmol/L in mid pregnancy and 200-700nmol/L in late pregnancy, there are some differences because of individual’s physical condition and diet, it does not matter as long as it is within the normal range. In early pregnancy, because the gestational sac has just implanted in the uterus, the development is not very stable and the progesterone value is low, which can easily lead to preterm miscarriage. Early tests are more frequent and are mainly used to determine whether the gestational sac is well developed or not. In the early stage of pregnancy, the progesterone value needs to be more than 30 after 6 weeks, which means that the development is more stable, and if it is too low, it should be treated with medication to preserve the pregnancy as early as possible.