I used
Prometrium for 2 of my pregnancies, I also have
PCOS. I would start 2 days after ovulation and take it until either I got a BFN, (af usually shows up 2-3 days after stopping) or until 12 weeks. From what I understand, I don't think that it helps with ovulation, cause in my case I would start 2 days after my ovidrel injections, I think it is supposto make the lining thicker for the baby to implant and af doesn't come until you stop taking it.