I noticed a hard lump behind my right ear today at around noon, I saw a walk in clinic doctor and he told me it is probably something I have always had and never noticed, but I know for a fact I have never had a lump that big there and its very tender, what could it be? My ears do not hurt, I am not ill in any way, though I did just get over a common cold , it is not red or pussy looking its just a large hard lump....