Is my uneven pelvis a symptom of my scoliosis?

Scoliosis. Scoliosis is a condition of curvature of the spine. The spine and pelvis are a continuous unit, like a stack of blocks. It is very likely that changes in your pelvis are compensating for the curvature of your spine in order to maintain your body balance. Consult an osteopathic physician or chiropractor for spine and pelvic alignment treatments.
Probably. Though if the scoliosis is mild, other causes are also possible, such as leg length inequality, whether actual or apparent. Given a history of scoliosis though, that is the most likely cause.