Missed adding a 1099 INT to my 2019 tax return

Hi - I filed my taxes on April 2 and it was accepted on April 3.  After submission, I realized I forgot to add a 1099 INT from my Mortgage servicer of interest income of $15.

 

I got my state refund within a few days, however Federal is still sitting in "return received" with today being 2 weeks since filing.  I am expecting a refund from federal as well.  Should I file an amendment for this missed 1099 INT income of $15 or wait until I get my refund and then amend?