When you log in to your TurboTax Online account, you can check your filing status on the welcome screen. If you have completed and submitted a return to the IRS (or your state), this screen will show if the return(s) has been accepted or rejected (see attached screenshot for an example).
The IRS doesn't officially open until 1/29/2018 so they won't begin processing returns until that time. Once they open, the return will process and finalize and they will begin sending refunds.
Also, if you also filed a state return, that return will not process until the federal return has been accepted by the IRS. So, you may see a started or incomplete status for the state return as well.
- Note: If you started a state return and didn't finish it you will need to log back in to your TurboTax Online account and file it after the federal return has processed.