Engine noise

I have a 1998 k-1500 5.7L, automatic, Z-71, Ext. Cab sportside, Canadian made, 86,000

I have put on an Air-raid after market breather and an air-raid spacer, these are the only modifications made.

My problem and/or question is when I first bought the truck (used, 2 years old 36,000 miles) I could hear a whining sound from under the truck near the drivers side frame. I was told that the noise is my fuel pump running. Others have told me that I shouldn't hear that sound from my fuel pump. This past weekend I went to the dump, 10 minute drive, left the truck running and proceeded to a lawn sale, turned truck off, after 15 min. Went to start truck and it wouldn't start. Battery good, after cranking it over for 10 min I couldn't smell any gas. I don't hear the whining sound anymore, have changed fuel filter.
Is my fuel pump gone?