Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers.
I've been following various people's posts about the GRE for 10 months now. Some people don't study at all for the GRE, some study for a weekend, the average is about 2 to 3 months, and some study for a year or more.
Doing well on the GRE can require a good deal of preparation. Although the exam's designers say the it's intended to measure only general ability -- meaning you shouldn't have to study for it -- that doesn't mean it's a good idea to simply walk in on exam day and hope for the best.