Hey Xmas,
Do you notice more sweating or salivating as well as the twitching. These are symptoms of possibly taking too much Mestinon. Definetly call the doc and see what they think.

Too much can be as bad as not enough, and increase the weakness as well. I have had twitching alone that didn't worry me too much, and I've had the overdose symptoms.

It's a tight rope sometimes, but you'll get familiar with how much you need as you gain experience. Let us know how you're doing and what the doc says, ok?