Need answers Please

I have PCOS and Every month I get my period. My Dr told me because I get my period that mean I ovulate each month..i am on Metformin and I have been on it since last year January 2017...I did get pregnant I’m July 2017 but had a miscarriage carriage in August 2017... I been taking Metformin consistently and nothing has been happening...I continue to get my period each month on the regular...I use ovulation kit each month and have sex throughout the week when I’m at high fertility and when I’m at peak....has anyone experiencing the same thing...can anyone explain what is going on within our bodies that is causing this delay, especially when we are getting our period each month, which mean we are ovulating.. I need answers