Faint line in AM and then not pregnant on digital in afternoon

Erin

I didn’t think to take a picture of my tests but I got excited when I saw a very faint line on my test first thing in the morning. I second guessed it all day and took a digital in the late afternoon and got a “not pregnant”. My period is 3 days late. How long should I wIt to take another test if my period doesn’t come?