Hi, Im tabi age 28, ttc 8 years having pco ,im using metmorfin 500 mg 2 tablets twice a day, but still serum insulin is my tsh is 5.23, for tht doc suggest me thyroxine . My last cycle was of 20 days only after using these medicine my periods r late last periods were on 8.2.2013, and now its 12.3.2013 still missed period with negative pragnancy testwhat should i do for this why this happening is this due to thyroxine?