I keep feeling a sharp pain in my side.what could this be?

Could be many things: Depending on the severity, timing and location the pain could be due do food in sensitivities, problems with your gut, kidney, gall bladder or appendix , constipation or diarrhea to name a few. If the pain is severe, prolonged or just causing significant discomfort, get checked out by your primary care and they can help determine a plan of care.