So weird!! Any one else have this problem?

Beth • Newlywed with 7 and 2 year old girls .. trying for #3
I keep getting a faint positive on every blue dye test I take but a BFN on every pink dye test.. I have 4 faint positives on 4 different blue tests (EPT, Equate, and Target) and negative on FRER and the $0.88 Walmart ones.. Don't understand. Is that normal?