Will amending delay my original tax refund?
No. You'll still get your original refund, amending won't delay it.
However, if you're amending to claim more money, 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.