?? About clear blue pregnancy test

So I am currently 1 day late on my period and I took a test 2 days b4 missed period which was a dollar store test and got a negative so today I took another one the clear blue test and I seen a very faint line in the first window and I mean like barely but the second window had 2 lines has this happened to anyone I can barely see the faint line in the first window but the second window you can clearly see the second line in the 2nd window just wondering if it could be a faulty test.. I am going to wait till morning to retest but figured I would see of this has happened to anyone else b4