When can you rule out ALS?

[HI50]

Like everyone else I have been stressing out with the worst case scenario of ALS.  I am a 38yr old male who was working out regularly until 6 months ago due to changes in job.  My symptoms started 3 months ago with tingling in my right leg for a week that then moved to my left arm.  After two weeks the tingling went away and I felt that I had weakness in my right arm with tremors in both arms and my right leg would feel weak with tighness.  I saw my GP and he suspected a compressed nerve possibly as I am a Pilot who sits for long period of time(6-8 hrs+).  To alleviate my fears I had a MRI with contrast of my head and cervical area, all clear, also perfomed blood tests thyroid, iron, arsenic, lead...all came back negative.  At this point I asked to be refered to a Neurologist which I saw four weeks ago.  At this point I had also developed muscle twitches that move all over my body but are more focused in my left bicep and right calf.  Neuro did his exam and said he could not find any clinical weakness and no observed twitches, but did say I have essential tremor and prescribed inderal.  Did NCV of left and arm and leg and an EMG of my left arm and said he could not find any Muscle or neurological disease just slight carpal tunnel.  I asked if this ruled out ALS and he said at this time I do not have a disease but he cannot tell the future which wasn't very reassuring for the anxiety I have been feeling.  I had been under alot of stress when this all started  due to the loss of my job, but that situation has been fixed but now all I want is answers.  

1.  With only 10 weeks of feeling weak and twitching for 6 weeks is it too early to find anything?
2.  Does ALS twitches come after the weakness and atrophy or when?
3.  If not neurological then when is causing the stiffness in leg and ache/weakness in arm?
4.  I have been told there are no sensory issues with ALS(tingling) which I had but haven't seen for 7 weeks?

Thanks for any help.