Going on three weeks now on Metformin, still no period, and I've had none of the side effects it's…

Going on three weeks now on Metformin, still no period, and I've had none of the side effects it's supposed to have. Everyone says it does terrible things but I'm taking 2000mg a day (2 in the am, 2 before bed) and not so much as a twinge? Are they even doing anything? 3 weeks with no changes at all seems bad to me. I can't afford to see an endochronologist, these pills are literally my only hope of conceiving, unless I win the lottery sometime soon. Has anyone had metformin work for them but not have any symptoms? Everyone it was successful for seems to have horror stories about their cramps and vomiting...