Hello. Welcome to HCM
You had appendicectomy few years back. Local pain will not persist for so long. But minor abdominal surgeries may cause adhesions and intra-abdominal bands which can cause altered bowel motility and thus lead to vague lower abdominal pain
on both sides. Pain exactly opposite to side of appendicectomy needs to be investigated by at least an ultrasound
.Make sure you eat healthy with plenty of dietary fibre water intake. If pain persists and is severe you need to visit a gastroenterologist and get investigated at the earliest. Take care.