SIJ pain?

Has anyone else here experienced SIJ pain in their pregnancy? I keep feeling this pain in my lower right side of my back, kind of at the top of my butt, like it's stuck and I need to pop it back in place but I can't, so whenever I bear weight on that side I get a pain that shoots almost from my lower back to the bottom of my right buttcheek. One of my clients is a maternal physical therapist and I was talking to her about this, as she was watching me work (I do Brazilian waxes) and she was like "YUP classic SIJ". She told me to get a belly band. Does anyone else experience this??