Helly, choose whichever setting you like, yeah it says for experts but try them anyway, you can always switch it back, it will just say due to new settings it is changing your date or this is for experts blah, blah, blah. FF did that to me last cycle, said I O'd 2 days after I thought I had and my cm had changed. I think my temp taking must be seriously unreliable. Or maybe it is the fact I have been told in the past I have non-restorative sleep, hmm, food for thought.