I've found a little lump behind my earlobe close to the mastoid bone. Its not visible but I can feel it, so not on the surface of my skin. It's pretty close to the muscle or tendon on the side of my neck beneath my ear. It feels about the size of a lentil and firm but not particularly hard, like it could be fatty or gristle. I don't think it's a lymph node, as I think that would be larger like a pebble? It seems a trivial thing to bother my GP about, but I keep touching it, and it is bothering me. Is it likely to be nothing to worry about? It's hard to tell if it's attached to anything.