Breast incision question

B

Long story short, I got a small benign cyst removed from my areola/nipple mid September. No stitches, just glue on the 1 inch incision. It healed well, got checked on and everything went fine. My question is, why is it painful internally still? It was my first real procedure and just want some insight. I will be calling my doctor if it persists but was wondering if its from scar tissue forming or anything? Picture was a week after surgery.