Hi Sarah,
I agree with Frank, you should definitely get check out by a neurologist, and one who is an MS specialist. I was just diagnosed, and my flare-up was numbness in my head/ears, stiff neck, buzzing feeling in my torso and legs, and pins/needles throughout my whole body. It took a LOT of testing (MRI's, evoke-potential tests, LP, ultrasounds, etc) to diagnose me, but my reflexes and standard neurological exam were all normal.
I started with a general neuro but now switched to one who specializes in MS. He said that I'm very lucky I was diagnosed because only one of the many MRI's showed my lesions and it was an MRI specifically ordered up by neurologists to diagnose MS. They did use contrast for the MRI and the lesions did not show in the MRI's without contrast. The first MRI I had in the ER looked normal and the doc came back and told me my symptoms were made up and I had Generalized Anxiety Disorder.
Not trying to scare you but you should definitely push for all the tests you can get, just to be sure. Better to catch it now than down the road... this can be scary but you're not alone.