Evap line or possible positive test?

I took a pregnancy test today and noticed almost immediately that there was a faint and small spot of blue dye at the top of the test window. I've taken a couple pregnancy tests over the past couple days, and all were completely negative. I'm about 7 days out from my next period. Could this be the blue dye running? Or does any color mean it could be positive?

I usually don't buy the blue dye tests because of there bad rep, so I don't know whether to trust the results or not. Let me know what you think!