scared of ALS

Hi,  this is my first post.  I am really nervous.  I am 36 y/o female who has been experiencing fasiculations in my legs.   They move around, from  my left calf to my right, to my foot.  Never above my waist.  I am an anxious person by nature and are very aware of myself.  The last few weeks my left leg has felt funny.  Like a stiff or heavy feeling.  i do my jogging with no problem and dont notice any weakness.  I had an EMG about 3c months ago that was negative.  What do you think.  All I cam think about is that I am doomed and I have small children at home.  Help!