Return and letter question

[S1993]

I filed with TurboTax and the IRS accepted my return on the 10th a couple of days before they were officially slated to start accepting. Yesterday morning, I noticed my federal return was ALREADY deposited into my bank account. Today I noticed two things that seemed odd which is what my questions relate to. First, neither TurboTax nor the IRS website says my return has been approved let alone the refund. Second, I noticed in my USPS informed delivery account that I'm receiving a letter today from the Austin IRS branch. I am away on vacation for some time and don't have the ability to grab the letter and see what it says. 

Any thoughts or am I just being paranoid?

Thanks!

[fanfare]

IRS seems to be in a hurry when it comes to your tax return.