Sal: What is the best time to use the OPK, my cycle is so irregular and my temperatures are up and down, there is no constant and I dont get very mcuh CM, so its so hard to tell when Im about to O or have o-ed using previous charts. I used the OPK on the off chance of that i was O-ing. I use fertility friend as well, but havent not got a coverline and it has NEVER predicted ovulation. Any advice ?