i have been put on metformin due to pcos to help me loose weight not to concieve i have been pretty damn lucky with the side effects really to date but this month i have really painful breats and the veins are really visable the only time my boobs hve been this painful is during pregnancy it hurts to sleep on my front and it's painful without the support of a bra could this be a side effect of the metformin is it my hormones kicking back into action do you think? you see i can't be pregnant my OH had the snip about 10 yrs ago between that and my pcos i am not gonna be preg! i don't think it is entirely pms as it has been on and off throughout the whole month!