X-rays show bones, MRI's show tissue. Get an MRI...one with contrast if at all possible.
Don't waste any time in getting that MRI. Sounds like you're having the same sypmtoms I did. The docs told me I pulled a muscle. 6 weeks later, when it hadn't gotten any better, I pushed to get an MRI and I had 2 herniated cervical disks. I would ditch the chiropracter and get into physical therapy with massage and ultrasound. Good luck.
I've been experiencing pain in the same area, seeing a Pysio Therapst three times and then getting reffered to a massage therapist, the RMT is amazing they don't just massage they fix and give you stretches, it's wonderful.