BFN until AF???

Please please answer if this has ever happened to you!! Has anyone tested with FRER’s up until their expected AF and got BFN’s and then a BFP after it passed? I’m supposed to start tomorrow and I got a BFN yesterday and I basically gave up lol. I accepted the fact that I’m probably out this month but in the back of my mind I’m holding onto the slight chance that I could still get a BFP. We BD LOTS this month and I track my ovulation. I normally get period pains the day before and the day of AF. Very very bad cramping! But I’m still having these dull cramps that I’ve had every day since I ovulated.