TurboTax gives you an estimated date of your refund. This estimate is based on the IRS statement that most refunds are processed within 21 days. Once the IRS accepts your tax return, TurboTax has no way of finding out any information regarding your return. The best way to get information is to use the Where's My Refund tool on the IRS website which you have already done.
IRS representatives will be able to research the status of your refund since your return was accepted more than 21 calendar days ago. Call them at 1-800-829-1040, but prepare for potentially long wait times.
The following TurboTax FAQ explains possible reasons why your return may be taking longer to get approved.