So my Af was due 12/12 but I got a positive OPK on 12/15. I had a blood HCG test and it came back negative. Doc wants me to wait until 2 weeks late to test again. But I was just wondering if its possible or if its happen to anyone... to ovulate late and get an accurate OPK with PCOS doc said it could be invalid but to be on the safe side test again before starting my meds(progesterone, metformin and clomid) and has any one been on said meds and conceived???