Progesterone is a type of estrogen released by the ovaries. After ovulation in normal women, levels of progesterone rise in the body, usually peaking within 7 - 10 days. When the ovary is not functioning properly, progesterone is not produced enough to provide a suitable endometrial environment for ovulation, resulting in difficulty in conception. Pregnanediol-3-Glucuronide (PdG) is the main urine metabolite of progesterone and is positively correlated with blood progesterone levels. PDG Urine Test can detect whether the PdG level in urine is elevated, PdG levels can be measured for several consecutive days to assess ovarian function and determine ovulation.