Pink vs blue dye test

I am late for my period. I read pink dye is more accurate and took 2 of those. Both came back negative so im wondering if i should get a blue dye just to see and be sure. Im about 3 weeks late. Both test i took were different days and different times. I have had pregnancy symptoms as well so im concerned about getting a false reading. I really dont k ow the difference between the two so im just wondering what you ladies think i should do.