Is fatigue in my left arm caused by neck problems?

[JChristensen]

About a month ago I noticed my left bicep felt strange down towards the crease of my elbow...kind of weak/sore...almost like there was a knot in it. I hadn't done any exercising...just my usual daily routine. My arm started twitching a lot. Immediately I was terrified I had some crazy disease. I had an EMG/NCV and all came back normal. All my blood work looks normal too. My arm still feels strange though. It just feels weak/shaky, but no actual clinical weakness. Sometimes it hurts in my bicep or elbow and sometimes in my shoulder. My neck has been really sore a few times over the last month and my chiropractor mentioned that my neck was really tense. The neurologist I saw for the EMG said he thought it was possibly an irritated nerve in the cervical vertebrae, but couldn't confirm that with the test since it all showed normal response. Has anyone experienced anything like this? It's been giving me a lot of anxiety, so any input is greatly appreciated. I don't know whether to request an MRI or what the next step should be. I see a dr again on Wednesday and I'm hoping she can help me figure this out.