Are you asking how many times do I have the discolouration? If so it happens every time I'm standing and let my arms dangle, even when I stand with what I think is 'correct' posture.

Also just to let you know the small bump that I felt has gone but the larger 'inflamed' area remains and still feels quite odd, almost as if somebody has got their hands around it and squeezing it. It doesn't feel like a lump as such, it's more of a fiberous tendon that goes from my neck to underneath the collar. I noticed that just below it there is a vein that if I keep pushed in with my finger it seems to pump up the vein a little which runs down the side of my neck.

Here's the first photo to show what I mean. The red line shows the vein and the blue line is the tendon thing which I don't know what it is, feels strange and is nowhere near as big as on my left side (I can barely feel it on my left).