Progesterone in the first month of pregnancy is normal if it is greater than 25 mmol/L. Progesterone secretion is pulsatile and unstable, sometimes appearing to decrease, usually not below 10 mmol/L; if it is below 6 mmol/L, the pregnancy is unsuccessful for now. In the first month of pregnancy, a blood level of more than 100 U/L of human chorionic gonadotropin is normal, and the ability to double it every two days indicates that the pregnancy is normal. If it does not reach this value, it is possible that the embryo has stopped developing or the pregnancy is ectopic.