The normal value of progesterone in the first week of pregnancy is 30 nmol/L, at least 25 nmol/L. If it is lower than the normal range, it indicates the presence of progesterone deficiency, which will reduce the stability of the fetus and lead to abdominal pain or bleeding, which may eventually lead to preterm miscarriage or miscarriage. When progesterone is low, it must be taken seriously. If it is below 10nmol/L or 15nmol/L, it is considered that there is a possibility of ectopic pregnancy. If possible, an ultrasound should be performed at about 40 days of pregnancy to rule out the possibility of ectopic pregnancy. If there is a possibility of 19nmol/L or 20nmol/L, it is necessary to take oral fertility medication as a precautionary measure to avoid frequent drops in the later stages of pregnancy, which may lead to preterm abortion. The progesterone and blood HCG should be rechecked as soon as possible after a week of oral medication, as long as they rise slowly, it means that the problem is not particularly big.