There's a not a single person in the world whose alignment will not be "off". I'm not a fan of doctors using Xray to diagnose or explain something. In my opinion, they should only be used to rule in/out a fracture.
In your case, the ab exercises you have been doing might have aggravated your back. What exercises were you doing specifically, and what were you trying to achieve with them?
I would look at your posture from ground up, to look for imbalances that could affect your hip and leg length. For example, an ankle injury could affect your foot posture and cause a functional leg length discrepancy.