If the progesterone is low, not taking progesterone may cause the following situations: 1, it will make the menstrual cycle significantly shorter, because the luteal insufficiency will lead to the luteal body atrophy in advance, so the menstrual cycle is significantly shorter. In addition, irregular vaginal bleeding may also occur after ovulation.2, due to luteal insufficiency can lead to the occurrence of infertility phenomenon.3, if the ketone is low in pregnancy, and do not take progesterone treatment, there is a possibility of contraction of the uterine smooth muscle, aggravating the situation of miscarriage, which will lead to the possibility of inevitable miscarriage. When found endocrine disorders, there is an abnormality when it is recommended to use medication accordingly under the guidance of a doctor.