Cd day 24 still negative opk

Has this happened to anyone? I'm cd 24 on my second round of clomid. We've been ttc for 28 months now. We were doing provera and metformin for months and now we added clomid.

I've been doing opks everyday since I stopped clomid two times a day and nothing. No positive ovulation yet.... last month I received a positive opk on cd 13 but the dr didn't want to do bloodwork last month (there was a miscommunication between the nurse and the dr) so we don't know if I ever actually did last month.

We start round three on CD 42. My doctor told me to only test out this week and then stop until next month. Has anyone ovulated this late on clomid before?

Losing hope that this will actually work :(