Hello, I recently have been placed on Metformin 1000 mg twice a day and 90mg of Armour thyroid. I take these for insulin resistance , pcos , and hypothyroidism . Despite the pcos, I have a regular 28 day cycle. I just dont ovulate regularly. My menses were due on 05/18/12 which makes my 7 days late. I have taken 2 hpt s, both are negative. Could this be a side effect to my new medication?