Akr it sounds to be you might be in for a nice early b day present tomorrow! If your cycles are 31 days and you normally get a pos opk lets say average cd15 it means you ov cd16 (roughly) so your lp is 15 days (wow tell me the secret!!) sooooo if today is 17dpo then you should have had af by today if you re not pg sooooooooo.....
Mom2sam if we assume 3rd feb as cd1 and ov on cd19 with an average lp of 14 you should expect (or even better NOT expect) af on friday 7th! Which makes you 11dpo!
Ladies i am THAT stupid and caved and tested on 9dpo with night urine (like 21:30!) and of course it was a bfn. I know you will say its early but i m so disappointed..this month has felt different and its probably all in my head