Why do I have to a tax due amount for PA when I am a NJ resident and these states have a Reciprocal Personal Income Tax Agreement?

Turbo Tax calculated a tax due amount on income that I earned in PA.  However I am a NJ resident.  I have already filed the return as a non-resident and scheduled the payment for April 14.  I realize now that this may be an error.  Should I file an amended non-resident return?