TTC but hadn't had a period for six months so went to see my GP. I was put on Metformin and the following day my period started! That was back in April and it hasn't let off since! It ranges from spotting to normal and there may be a day where it breaks every now and then but for the most part I am constantly bleeding 
Went to see GP who had no answers, went to fertility clinic who are equally dumbfounded and have suggested I go back on the pill to try to regulate my cycle
and to wait for my gynae appointment as they may have some insight but until the I have to play the waiting game.
Anyone else experienced this on Metformin??