Blue dye test!! Opinions please!

Okay so this month I had my first IUI.  Today I'm 12dpo and on day like 5 I was curious about the HCG shot and if it would actually show up.. And it definitely did. Then I tested again at 10dpo and it was very obviously negative so I took another the next day.  Same thing.  So I know that the HCG from the trigger shot was out of my system. This morning I took two Walgreens brand blue dye tests and got faint but positive test results.  I then decided to go get a FRER and I swear I saw a faint faint faint pink line but it won't show in a picture. Anyways.  Is there a chance I'm getting a false positive from the blue dye tests? I'm nervous to tell my husband incase I'm not pregnant