Hi, i worked in a dental setting for years.

What you're describing can be a lot of things. Could be a blocked saliva gland, could be an injury, an infection, nothing etc. Most turn out to be nothing. However, and it's a big however, the golden rule with any lump, bump, lesion or patch is if it doesn't go away within 2 weeks, you have to get it seen to by either a doctor or dentist. This is very important when it comes to the floor of your mouth or the rear sides of your tongue.

After 2 weeks, you do not employ a wait a see approach unless instructed by a doctor or dentist. Your oral cavity contains fast-growing cells and you don't mess about with that malarkey. But no one can tell you online what you have or don't have. Only an in person appointment with a specialist can tell you.