At The Doctor Yesterday, Pressure Put On A Muscle On

At the doctor yesterday, pressure put on a muscle on my neck (at the base of my skull) seemed to release a knot. It was suggested to continue massaging it out, which I have been doing over the course of the past 24 hours. However, this lump/knot doesn't seem to go away...it's still there after really trying to work it out. Is there a chance this could be something other than a muscle knot and by "working it out" could I be spreading it?