You can check the status of your return (pending, accepted or rejected) by logging into your TurboTax account or using the e-file status lookup tool. A link is provided below.

https://ttlc.intuit.com/replies/3319882

If you need to amend to claim more of a refund, the IRS says to wait until you've received your original refund before filing an amendment. Once you've received your original refund, feel free to cash or spend it while your amendment gets processed (this can take 12–16 weeks).

Three weeks after you mailed your amendment, you can start tracking its progress at the IRS Where's My Amended Return? site.