PLEASE HELP!!!!

Ok I bought 3 FRER pink dye tests and 2 Wal-Mart brand blue dye tests ALL 5 taken over 4 days were faint positive I got these 6dpo to 9dpo now I'm 11dpo (at least that's what the app says)and I bought a bunch of cheap 1$ tests from dollar tree (pink dye) so I can make sure the line gets darker but I just took one with a 7 hour hold (not a ton of liquids) and its negative! Please tell me this is not another chemical pregnancy what else can cause this?