I'm having right lower side pain no appendix did have a carcinoid tumor on appendix. Had c-section 7 months ago.

See your doctor. you need to see your doctor to rule out any problem associated with the carcinoid. it could be ad hesions from your previous surgery.it could be an ovarian cyst .the list is long. see your doctor for proper eveluation and treatment.
Could be. caused by the scar tissue , or from an ovarian cyst, mesenteric adenitis is another possibility ,could be pelvic infection . You may need a ct scan of the lower abdomen. See your doctor.