I failed to enter my 1095A form so I have amended my return. I haven't received my refund from my original filed return but what if I get it in the meantime?

If you have mailed in your amendment, then they IRS might make the adjustment before they process your original return. 

Or, they might contact you about updating the 1095-A form.

Or, they might process the original and then process the amendment. 

If you receive a refund before they process the amendment, you would only have to pay back any difference between the two returns.