Christina, did they diagnose you with a hiatus hernia? These can slide up and down, and with any wretching at endoscopy that can cause it to get worse. I remember when I had my endoscopy the dr said he could see my stomach herniating as I wretched.
Its most likely the biopsy site though, they literally cut out a chunk of your esophagus, so much like if you got a paper cut, it takes a while for it to heal over. If you have reflux then that will be irritating the cut but you should hopefully be symptom free once its healed if you didnt have symptoms before. Heartburn pain can be quite transient, sometimes in the chest, radiating to the side or even back. This is normal so no need to worry about it.
GERD, Anxiety, Depression, Rolling Hiatus Hernia, Visceral Hypersensitivity, Chronic Nausea & Stomach Pain