I'm 21 and have been diagnosed with pcos. I have never had a regular period. I started taking birth control pill cerazette last November and have had 2 periods since, so the medication hasn't stopped them. I've recently been prescribed metformin 500mg twice daily for the pcos and was wondering if it could regulate my periods even though I'm still on the pill. My doctor said it will help slow down the hair growth and acne but I forgot to ask about periods. Any advice will be greatly appreciated.