White painless bump on inside cheek

what should i do, i have braces and this bump has been reoccuring once in a whilebelow my braces(not on gums)and im kinda scared my doctors said not to worry about it but recently it got bigger being that you couldnt even tell it was there esterday. its painless and its white kinda clear they said check back with them once my braces are off. i have smoked tobacco before and i have done snuff, but who hasn't. im scared what should i do about this becuase it goes away for a little while and than it comes back, i picked at it once or twice and it has come off, what should i doooooo