@JAKYLYN-W - it depends. the 21 days is simply Turbo Tax's estimate and not a guarentee of how the IRS will operate. Turbo Tax has no idea how the IRS is processing, so I never understand why they even post that 21 day commitment.
it depends on the complexity of your return, whether you efiled or paper filed, whether the IRS pulls your return for closer review, etc.
Have you filed yet? you can review the progress at this website:
https://www.irs.gov/refunds
