I have already filed my taxes and how do I know if I will potentially get a refund once the IRS recalculates my gross income applying the $10,200 Unemployment tax break ?

The IRS is saying that they will handle it on their end. They do not want amended returns. It may take a while as they are very backed up.

If you filed before the law was changed, and your AGI is below the cutoff, you will get a refund.

There is no doubt about it.

If you already filed and didn't get the 10,200 unemployment exclusion you do not need to amend.  The IRS will be adjusting it for you.  See,

https://www.irs.gov/newsroom/irs-to-recalculate-taxes-on-unemployment-benefits-refunds-to-start-in-may

If IRS is going to amend it on their end shouldnt I still receive my original refund amount and get the amended later? My return was accepted February 13 and have already received my state refund which was accepted March 8.