Is It Safe To Take Metformin To Treat PCOS?

My doctor put me on metformin about 2 months ago to help with my pcos because I am trying to get pregnant. I take 500mg 2 times a day. I m 18, 120 lbs and I dont have diabetes. I m a little concerned because everytime I take the medicine I take it before I eat. I check my glucose and it s always in the 60s. It has been making me feel sick and I m always shaking and i can t even get up. Is 60 normal? And should I be feeling the way I do?