What is this bubble on my scar? (Photo)

I am 11 months post op. 430 saline sub-pec. I had a lot of trouble with the right infra incision healing and it required debridement 3 times, the last being July 27, 2016. All was well until today I felt an irritation along my incision line and notice my scar was bubbled out. I can feel the implant under the skin. What is going on?