I have taken about 8 pregnancy test all different brands. The first ones I took were blue dye test and they both came out positive. After about 3 hours they faded and you couldn't tell they were positive. I then took digital ones and those came up postive. I then took pink dye test and those came up postive and have not faded at all. I guess my question is....why are the blue dye test fading and the pink ones aren't?