Moni, Good, I'm glad you checked that out with your doctor.
Mestinon only helps with symptoms and not the "cause" of the lack of acetycholine; meaning it does not suppress the immune system and the antibodies.
If you had a bad headache and a minor backache, Tylenol may help to get rid of the backache but not all of the headache. It's the same with Mestinon. It may make the more minor weakness better but not more severe weakness. Depending upon what muscles you are using, you can have anywhere from mild to more severe weakness. Crazy, right? And if you take too much of Mestinon, you can have overdose symptoms (increased weakness). That's why some doctors increase the frequency of Mestinon before the dose. Some go back and forth (increase frequency, then dose or vice versa). Everyone is different. And you may need more at certain times, like when you are out in the heat or when you are sick. Those are only two things that can make MG worse.
When muscles get weak they can feel like they are "burning." If you've ever run a long time or been an athlete, you've experienced that feeling. People with MG just get there quicker!

Muscles can also cramp and spasm. MG is all about weakness but there are secondary problems that come from weak muscles.
I like how you said your face is "messed up." After I run errands, my face feels like it's going to droop off. I hate it. Fatigable weakness is never normal. They should do a SFEMG (Single Fiber EMG) on you.
Are you on Advair, by any chance. Or Flovent? Since you have allergies, I thought it was worth asking. Steroids can make those blood tests negative, as well as the EMG's!
Any other meds you are on that might interfere with tests?
I hope you get answers soon. If it is MG, it may take awhile to adjust to. Your mind will always want your body to do what it used to! It's harder to adjust mentally than physically, at least for me it is.
Annie