Ellie- Well, I this is only cycle #3 off BCP. Cycle 1: 27 days, then 31 days (that's when we traveled to visit family. Pretty sure that affected things), I'm currently on CD 24. I set Feb. 1-7 as my expected fertile window. My cm has been pretty unhelpful this cycle in figuring out ovulation, but I had some cramping on the 4th and 5th so I thought it might have happened then. On the 8th though, I had a really achy uterus all day. I'm thinking that's the more likely date now. But I don't know. Hence the OPKs next month!
I'd like to try out SMEP because the system DH and I have been using is BD every day in that fertile period. And it seriously knocks me out for the next week! He thinks we need a more "consistent" approach.