Does anyone have a bfn the first day they are late? And come out positive later?

Larainne
My fiancé and I have been trying for about 3 months now My period is four days late which is the latest it's been I don't want to test again because I tested the 22nd which came to a big fat negative. My only question is has anyone had a big fat negative the day they were late and came back a week later and was positive?