I noticed my stomach pulse whenever i first learned i had acid reflux/gerd is it normal asked doctor and said that im fine why is it can it be aaa?

Certainly, but...: Often, when we are diagnosed with one ailment, it changes how we perceive our body's natural state. Depending on your body habitus, you may have always had a palpable pulse in your abdomen. You may not have noticed it before you got a bit focused on your recent diagnosis. An examination by a doctor and some simple imaging tests would be the best way to rule out an abdominal aortic aneurysm.

Pulse in abs: It may be but probably is not. Would be extremely unusual in a patient as young as you. A simple abdominal ultrasound would answer the question for you.