I get pain in my left side and it sometimes swell up what do i do i went to the dr but he said its an appendix infection?

Left sided: Acute appendicitis usually results in right sided lower abdominal pain and tenderness. If your symptoms and signs localize to the left lower abdomen, I would suspect diverticulitis of the colon,inflammatory bowel disease or pelvic inflammation. Either way, I recommend urgent evaluation in the hospital emergency room or by an abdominal surgeon first if your symptoms persist. Need appropriate tests