How long after a neg or fl did you get a bfp?

Hannah • Fur mamma. Heathen.
Hey y'all. I see the faintest line on my pregnancy test that I took yesterday. I am now 4 days late for my period. I am never late. 
Just wondering for those of you that had a negative and a positive later on, how long did it take you to get a positive? 
Should I wait a couple days, a week? I have one more pregnancy test but I don't want to waste it because they're so expensive haha. 
Here's my test from yesterday just in case any of y'all see the tiny line I see.