You can go to the IRS's Where's My Refund page to check the status of your refund. After your refund is approved, there will be a message stating the date the IRS plans to send the refund to your bank.
If it has been over 21 days since you filed your return, and you haven't yet received your refund, we recommend contacting the IRS directly. The contact number is listed in the TurboTax FAQ below: https://ttlc.intuit.com/replies/3302084