Faint line on blue dye tests only

I have taken 4 blue dye EPT pregnancy tests and 2 of them turned positive after hours and the one from yesterday and today gave me a very faint positive line within the 2 minutes. Now I'm at my medical clinic and their urine test came back negative. With all four of my EPT tests the line is just as thick as the control line and its blue tinted. I am still 3 days before my missed period... It's driving me nuts could the blue dye tests really give 4 false positives?? Every single pink dye test is negative.