quadricep spasm

my lower quadricep has bein pulsating lately usually after I get home from school…. its bein occuring for a few days now and doesn’t go away till I go to sleep and then goes away when I wake up the next morning… but continues after school… im not doing anything over aactive I stretch before going on the mile run every other day… I eat healthy and I get the required sleep…. it started about 4-5 days ago and has bein reoccuring ever since for long period of time… it doesn’t hurt but I can’t feel the muscle pulsating and when I look it moves when it pulses.. like I can see the muscle move… im not sure what to do I have looked through many books and online… but most book references talk about tremors or shakes nothing really about spasms… that and most of those references talk about pain and swelling.. mine isnt swollen and I don’t feel pain.. but I can feel and see the muscle move.. either while laying down or standing… im really don’t know what to do but I would like a second opinion on the situationif u could get back to me as soon as possible I would apreciate it…