I had this as well every time i took it. No dr has had an answer but after research I found it could be endometrial hyperplasia. I would ask your dr to look into that. Good luck. I hated metformin!
Metformin is not suppose to bring on your period, any chance this is your period and it's just really heavy this month? Are you TTC? If not then maybe your doctor could recommend a birth control pill to help your cycles be regular. Or any chance you could be pregnant? If the bleeding continues, I would consult your gyn and seek their advise.
Hi i have been taking metformin 1000MG twice a day and i have not once, had any signs of abnormal bleeding, i did how ever had a very long period while i was on progesterone. i would definetly call YOUR doctor! ASAP!