BFN day before AF due, BFP later ?

Kristen
I'm due for AF tomorrow and I'm being impatient as always, i took a test 7DPO neg (I had a light period last month so I tested early incase)  and now I'm 12DPO and another negative. 
Just wanna hear some stories about woman who had a BFN the day before their AF was due later to get a BFP