Confused

Hi everyone I'm due for my period today and only got the chance to test tonight... So the cheap online test came up with a very faint line I got excited and decided to test on the clear blue digital and it was negative......... I then took apart the digital test just to make sure ( as you do lol) and there was no line on either of the strips so now I'm thinking that it wasn't accurate just wondering if anyone else has had a similar experience???