hard lump on inside of lower mouth?

[NatashaKimberly]

Today after I brushed my teeth, I rubbed my tongue along the lower part of my mouth, and when doing so I came across something odd. It feels like a hard little ball, its about the size of a pea. It does not hurt unless I put a lot of pressure on it. I tried to see if anything came out and saw nothing, but at the same time it is brand new, it wasn't there yesterday. Does anybody have any idea of what this may be?