The unit of test may vary from hospital to hospital, and the unit of conversion is different from hospital to hospital. If the unit of reference value of the laboratory test you get is ng/ml, you need to multiply it by 3.18 to convert it to the unit of nmol/L. If the progesterone is lower than 17 nmol/L, it is usually considered as low progesterone, which is mostly caused by luteal malfunction and may lead to preterm miscarriage in serious cases. You should take progesterone or progesterone injections to improve your progesterone level so as to ensure normal fetal development. Avoid sexual intercourse as much as possible in early pregnancy, and also ensure a reasonable diet, actively replenish the nutrition required by the body, ensure good sleep and do not overwork.