i understand what you're asking, and in a simple answer: no, you would not change scales every time you change chords. this goes into what chords you are playing, though. if it is "diatonic" (or the roots of the chords are found in the scale and no notes of the chord violate the notes of your scale) then you can rock and roll your way to the bank with just one scale. changing scales gets more into classical and most definitely jazz playing. classical pieces modulate to different keys, obviously warranting a new scale, and jazz music contains extended chord harmony (9ths, 11ths, 13ths) that will sound bad against your diatonic scale at times, so jazz players work in "changes" (they outline the scale tones relating to the chords being played) but that's heavier than you want to be in at your state of learning, so just focus on the easier stuff, like rock/pop/metal/blues/reggae/what have you.

hope that helps.