What is this odd popping sensation in chest muscle after implant removal?

I had my sub muscular implants removed 16 days ago, local without any capsule work. I am very happy with the results, besides the fact that I have a small seroma in both breasts. My question is about this muscle popping sensation that I keep getting on the outside of my breast near my ribs. It's quite uncomfortable. I actually had this sensation when the implants were in, whenever I extended my arm and I always assumed it was the implant, but it hasn't stopped now that they are out.