Good advice above--it takes time and it is also a process of elimination. Have they checked for Lyme disease? it mimics MS.
Fibromyalgia can cause deep tissue pain and also can mimic MS. It's a tricky diagnosis, but the rheumatologist has markers on the body to tell if it is fibro.

As Judy said, keep a symptom journal. Get plenty of water and rest, and make sure to move daily, be it exercise or a nice walk. Try to live life to the fullest, whether or not you eventually get diagnosed with something.