Can you still have acid reflux if your upper gu came back normal?

Of course...: Gastroesophageal reflux disease (gerd) involves movement of stomach contents back into your esophagus. Gerd can be "silent" in a substantial # of patients, manifesting with ear/nose/throat ; lung problems without heartburn. Heartburn is the common presentation of burning discomfort in your chest with exposure of the esophagus to stomach contents. See earlier healthtap answers for gerd prevention.

Reflux and Upper GIs: Yes , you can. An Upper GI is just a radiologic study to assess the internal structure from mouth to stomach and sometimes first portion of small intestine. It makes sure there are no areas of narrowing or obstruction. It may show reflux in some patients but the study is not designed for this. To determine reflux you may need an endoscopy with biopsies or a pH probe/impedance study.