Yes, waiting for the results of a test for MS can be really stressful. The diagnosis of MS is based on several factors such as signs and symptoms (not distinctive of MS but patients usually have neurological signs and symptoms), MRI findings (may not always be positive), and findings of lumbar puncture.
Diagnosis of MS is complicated as no single diagnostic test is confirmatory. However, more than 90 percent people are diagnosed based on MRI only, which shows multiple demyelinating plaques. The number of plaques increases with MS flare. Neurological examinations reveal weakness and other signs. Evoked potential tests are done to diagnose nerve weakness. Lumbar puncture or spinal tap is also confirmatory for MS in 80-85% of the patients showing signs of chronic inflammation and oligoclonal bands.
So, if MRI is positive for MS then there is a chance you have MS. The diagnosis will be more certain once the lumbar puncture results are available. Please discuss with your doctor.
I sincerely hope you will find this information useful in your journey towards better health.
Hope you get well soon! Good Luck and take care!