Hello I Was Having The Problem Of Irregular Periods And

Hello
I was having the problem of irregular periods and diagnosed with pco...I got periods on 8th of july with withdrawl bleeding and started meformin after that. its almost a week now rather than irregular periods i am having amnehorrhea. I took 2 pregancy tests they are negative still and feeling too much bloated, backache and heaviness and pain in tummy.
Need guidance