It's possible that the IRS is examining your return but it's hard to know if it's because of the stimulus or something else. When the IRS accepts a return, it means that their scanning didn't find any mismatches that it has to pass before the numbers and calculations are performed.
Here is a TurboTax article with the latest information about the third stimulus payment.
If you didn't receive your stimulus and it went to the form of a refund due to the Recovery Rebate Credit on your 2020 tax return, please check this link for more information.
If you never received the stimulus at all and did not declare it on your tax return, please check this link.
