Hi Liz

I chart and do OPK's while on clomid. I normally get O pains around CD15, 16 & 17. How often are you doing your OPK's you maybe missing your surge and that's why you're not getting a + OPK. I normally take my OPK's at around 6pm. It's been aurate for me that was as well as having my temp rise. Perhaps you need to start testing 2 times a day once at around 2pm (that's the ideal time recommended) and then one later at say 6pm - 7pm?