would it be accurate?

I took a pregnancy test 4 days ago. I have kept it in my bad since taking it to check it everyday. I get very paranoid. After taking it, it was clearly negative. I checked a few times everyday to make sure and it was still negative. Yesterday I looked and it was all dried up even more and had a faint second line. It was grayish pink color. Would that be the incorrect reading since it stayed negative for so long?