I am experiencing nausea (severity: moderate) and abdominal pain (quality: burning) (side: upper) (severity: mild) .

Reflux possible: You may want to talk to your primary doctor about the possibility of reflux disease. Did you eat anything spicy, or with caffeine, or take Ibuprofen? These are common irritants to your stomach. It is important to distinguish this from a cardiac origin so if the pain is intensifying, please go to the ER. If not, take some Maalox, or gaviscon, or another anti-gas formulation and followup.