I have been temping the past few months to pinpoint if I in fact, do ovulate, and what day. FF usually put my O day as CD 17. I used OPK's this past cycle and got a positive on CD 15. When does O take place typically after the positive OPK shows up, is it 48 hours? I just want to get as much accurate information as possible to share with the RE when I meet with them. If it does take place on CD 17 then I know for sure I definitely have a LP defect (my cycle on average is 23 days). Thanks!