I had something post surgery that was similar. It was probably something my brain was doing, trying to balance me. The rocking has stopped, but I am still wonky 22 months later.
It might not be anything unusual. I think most of us, when we first get sick and identify it as part of an illness, like an AN, start to notice little things and associate it with the new problem. It might be something we have always had, but just ignored it just because it was normal behavior...ache behind the ear, walk to the left or right, etc. It might be a problem, so don't discount it. Make a note and discuss it with your doc on your next visit.