Like Donna, I had cramping with Clomid every cycle. It was generally my ovaries but pain nonetheless. I also found that I was able to feel absolutely everything that went on in the reproductive area. It may have been my heightened sense of awareness or my body playing tricks on me. Either way- I felt like a dog chasing it's tail!
Did your temp ever go up? There can be so many inaccuracies with temping and OPK's that it's hard to determine if you O'd without the P4 test. Will you have your Progesterone (P4) checked on cd21?
Clomid also has a tendency to increase the length of your cycle. Mine went from 28 days to 29-31. What a pain that was.
Good luck and I hope this helped a little.
Rhonda