I started Metformin at 500mg up to 1700mg a day now about 4 months ago. I went from a 100 day cycle to an average of 32-33 days for last 3 months. This month I got a positive surge on an opk on CD24 (started testing CD18 every day)..super late but my first positive surge ever! Now I'm on CD36 so tomorrow is 12 DPO. I'm hopeful but got a BFN on a pregnancy test today..later realized hpt was expired, anyone know if it makes a difference? I don't have any usual PMS symptoms, just tiredness and lack of appetite.