When did you get your BFP?

Sara • Two year old little girl already.. pregnant with her little brother! Due July 16th!
I am just curious if anyone has ever gotten a clear BFN ( no faint lines at all) the day before AF and then the day AF is due or after get a BFP? Just wondering if I should take my BFN this morning as AF is gonna come and go buy some OPKS for next month...