Hi Jamie!
It wouldn't surprise me if your doc is just holding back on making a definitive diagnosis out of some caution to double check things first. Often, despite certain indicators, they want to see if you respond to anti-inflams first, so I wouldn't give up on this doc just yet.
I do think it's odd that the doc doesn't consider your constant back pain could very well be due to an inflamatory process. Did she say if she was basing that opinion on bloodwork results? Since AS is sero-negative the indicators in bloodwork are not as reliable as they can be in other types of arthritis, so for some it can cloud the obvious somewhat.
I certainly hope you'll find these answers soon and not be given the run around. In the meantime please stick around, as you will find so many warm people here who can relate to your search for answers. Plus it is just such an invaluable resource for info!
Take care,
mig
