You only know for sure sure if you got a tracking number from the post office when you mailed it.
Sorry the IRS has limited staff due to Covid-19. They didn't start opening the mail until June that's been stacking up. Back in March the IRS closed their processing centers and stopped processing mailed tax returns. An IRS spokesperson said that they have about 11 million pieces of unopened mail. The IRS says....."We’re experiencing delays in processing paper tax returns due to limited staffing. If you already filed a paper return, we will process it in the order we received it." So it may take longer if you mailed in June or later. So you have to keep waiting.
See this IRS page for the latest information
https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
Is it showing up at IRS Where's my refund yet?
https://www.irs.gov/refunds/
Make sure you are using the refund amount from your actual federal tax return and not the combined amount Turbo Tax showed you at the end. That was for federal and state combined.