12 weeks post TT and experiencing burning pain at center of incision with a couple hard bumps. Why suddenly is this hurting?

I had a TT 12 wks ago and see my surgeon regularly. Everything has been fine (couple seromas aspirated early on). At 10 wks I felt some bumps in the center under the incision line. Bumps didn't concern me until I began to feel intense pain and burning. It's more pronounced when standing. My surgeon injected it with a steroid. 3 days later, It's still burning. Dr thinks it's scar tissue but couldn't explain the pain. I'd like some Opinions. If a revision is needed, do most doctors charge again?