Normal HCG and low progesterone can be caused by poor ovarian function of the mother and insufficient luteal function of the ovaries. In early pregnancy, women need to monitor the HCG and progesterone values to see if they are normal. Normal HCG values indicate that the gestational sac is well developed, while low progesterone may be caused by poor ovarian function of the mother and insufficient luteal function of the ovaries. Female ovaries can secrete estrogen and progesterone. If the ovaries are not functioning well, it will lead to hormone level disorders, and low progesterone will occur after pregnancy. Inadequate function of the ovarian corpus luteum after pregnancy can also lead to low progesterone. The corpus luteum is the main place for secretion of progesterone in early pregnancy, and its insufficient function will lead to insufficient secretion of progesterone. Low progesterone after pregnancy with normal HCG may lead to fetal preeclampsia, and if necessary, you need to use progesterone and dydrogesterone tablets under the guidance of a doctor to regulate.