Late period but no bfp until later ?

I am just curious to hear your stories. Was there ever a time your period was late, you tested and at first it was negative but later became positive? Af is 2-3 days late. Took a test this morning and it was negative. I know with my last pregnancy I was almost a week late and still was only getting very very faint lines. But I also know each woman and every pregnancy is different.