Okay so this is my 3rd month off BCP. 1st month AF came cd29 (28 day cycle) and 2nd month came cd31 (30 day cycle). Today is cd35 and no AF in sight and BFN on frer pregnancy test. I spotted on cd29/cd30 so not sure if that was possibly really late ovulation (since last month spotted on cd21/cd22).

But anyway at this point I am assuming not pg and cycles are just being funky.

If I skip a period this month when should i start using the OPK? I want to use them to help me figure out if or when i am ovulating?

Anyone experience this and if so should I just assume I had a 30 day cycle and start using them around cd40?