Hi, not everyone with MG show positive result in the blood test, especially when the symptoms occur only around the eye. If you feel your symptoms get worse over a period of time, you'll need to do the blood test again. There're other ways to test but blood test is relatively simple. The drug Mestinon - not mesotone, is basically fine, side effects are almost all related to over dosage. As long as you don't over take it, it's fine.