Just had a sharp pain from my belly button go up my esophagus several times. i was laying on my side. is it acid reflux or could it be something else?

Need to examine: It could be acid reflux, but it is not feasible to provide an informed opinion without examining you. If you are overweight, losing weight will help. Have a healthy diet, exercise 30 minutes/day, drink plenty of water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/.