Are your previous phones off? That can mess up a port over. Yes, porting can take days, but not usually with ATT and Verizon (straight talk can take 2 weeks because no one actually works there LOL)
My gut is saying your account is not set up right, or not set up yet. Please send a message through the forum by clicking here >>
The store where you picked up your SIM card may also be able to help you using the My ATT app.
I don't remember how long it takes for the account to be set up online....