My temp dropped today & I could swear I am O'ing... but the OPK I took this morning was light. The one I took Sunday morning was darker, but still not positive. I took a 2nd one Sunday afternoon, but it was virtually invisible (granted, I didn't make it the whole 4 hours because I really had to use the loo) I didn't use any OPKs Saturday because we were gone all day & there was no way I could have snuck it in (port a potty testing, anyone? LOL)
This is why I HATE OPKs. It never fails, they make me second guess myself.

(I haven't checked my cm because we are using those instead cups today)