Other causes of lower right abdominal pain are Crohn’s disease, diverticulitis, infection in kidney, constipation, ovary involvement in
women, ectopic pregnancy in
women (probably ruled out in
your case), or mesentry (a thin tissue that carries the blood, nerves and lymphatics for the intestine) involvement. Chances of Crohn’s disease or polycystic disease of the ovary are also high. It is difficult to comment beyond this at this stage. Do consult your doctor.
Hope this helps. Take care!