Bone at SI Joint Sticking Out

I know I may be in the wrong section for posting, but am posting here as it's the closest to my issue, which is sacroilitiis (inflammation of the SI joints)....so pain, treatment and inflammation of the joint are common with RA.

The inflammation has gotten pretty bad and am attemtping physio (of which from my other post, you can see it's hurting more than helping).  Anyways, I noticed that at my right SI joint, the bone actually pops out.  I know that I've been told that things are just misaligned so would it just be the bone shifting and part of that?  Should I be worried?  I just saw my rhematologist last week and don't see him now until November.  

It's strange as it's only my left side that has the bone portruding a bit.  It's sore to the touch, but my back has been sore and not great the past few days.  I do have a physio appointment on Wed so will ask.  What would a dislocation feel like?  Thanks for your response .  You're always helpful and supportive.