I'd return them, but I 100% don't trust blue dye tests unless they are blaring, and I like to test early which doesn't usually mean blaring lines... if you are testing at like 17dpo or something go for it, but honestly, you probably will want another test to mae sure anyway, so I'd save yourself the stress and get a better test. the dollar tree tests are fairly solid tests, the 5 day FRERs are good too. I have also had great luck with the purple dye equate +/-.