I have a rounded, smooth, painless, movable lump under the skin of my right lower jaw. Noticed it 2 months ago. For many months or possibly a year I've had slight pain in the right inner cheek when eating sour foods. The lump slides easily back and forth. It is in the submandibular area. I am 21 year old obese male. I am wondering the chances of it being cancer...I am comforted by the face that it is very movable and mobile, but still concerned. Does the movability rule out cancer for the most part?