I wasn't sure where to post this so I decided to put it here, I have had 2 ulcers on either side of my mouth at the back on the gum for roughly 6 months now. They don't hurt at all but can sometimes be irritating etc. (and I know I probably ought not to, but sometimes pop them, and they either seem to have a white puss like substance come out or just blood). But I was just wondering what is was, is it something to be worried about or will they eventually disappear?