How soon did you get a positive?

I have long cycles, usually 35-37 days.   I have no sign of AF, and I am currently 5 days late. I took a test the first day of my missed period and it was negative. But the test lines were very, very light so not sure the test was working. It was an EPT. (Blue dye) and I tested at night, if that matters. How long did it take for you to get a positive?