Dull Ache still after appendectomy?

I had a laproscopic appendectomy in August (6 months ago). It took almost 4 months for me to feel normal again on the right side of my abdomen. Had ultrasounds, endoscopy, colonoscopy...all fine. The dull, non descript aching finally disappeared in December for good! Then, about three weeks ago, I was playing an intense game of Just Dance and the next day it was back again, and hasn't left. It doesn't hurt, no pain at all, just like a dull achy kind of feeling. I am quite certain it's not a hernia, I was checked by my dr every month through December. Could it be abdominal wall muscles that are weak from the surgery? Scar tissue? Anyone else ever experience this?