Is the lower spine supposed to curve to the right when your're looking at an x-ray?

I have Fibromyalgia, RSD, myofacial pain syndrome, and chronic upper back pain. However, my ortho dr had me get a bone scan to see if anything else was wrong with my back since I always have severe chronic upper and middle back pain. Well he showed me the images today on the bonescan and my spine was straight from the top and the middle but at the bottom of the spine, it curved alot to the right. He wants me to get an MRI now to see what if anything is wrong. But is that not normal for the spine to curve to the right like that at the end? If not, does anyone know what that means or what that indicates I have?