Akka, your sensations have nothing to do with ALS, fortunately
Numbness etc are VERY rare.
Today, unfortunately, there isnt any test that can say "YOU HAVE ALS" or "YOU DONT HAVE ALS".
The most reliable is EMG (done after long enough period of time)on afflicted and even on yet not afflicted muscles. In ALS the finding is typicall - large motor units, signs of reinnervation (since with ALS your muscles are "disconnected" from damaged nerves but the body tries to repait them - reinnervate), positive sharp waves and polyphasic fasciculation potencitals. And of course fibrilations - "twitching" of muscle fibers that you cant see but those are bad signs.
Biopsy can also be very helpful since it can reveal damaged nerves and yet non visible muscle atrophy.
Remember, ALS is disease of weakness, everyone who start with different symptoms and is later diagnosed with ALS is very rare exception.
Fasciculations, even weakness and strange feelings can be caused also by:
M.gravis (very strong weakness with not many fascics)
Lyme disease
Multifocal motor neuropathies (sorry for spelling, I dont know english names)
Clamydial infection
Metabolic disorders
Autoimmune neuro diseases with loss of myeline
and MANY more..
but many of BFSers experience (except non stop twitching) numbness, pains n needles, percieved weakness...