Sometime I Have A Small Knot At The Base Of

Sometime I have a small knot at the base of my hairline due to stress that feels like a pressure point when you press on it. Today I noticed one midway down my neck between my hair line and collar bone. It seems to be where the artery runs through my neck and when I press on it it's not painfull but it is the same size as the knots that I usually get at the base of my skull. I also have systemic lupus