Faint line

Ra
So I took one of the clinical guard pregnancy tests this morning looked at it after maybe 45 seconds and didn't see a second line now I just looked at it again and there's a faint line. I know it's after the 3 minute rule but just wondering how many of you have tested gotten a positive when you looked at it again and you be really pregnant? I honestly thought I was out this month after 6 negative tests!!