I had surgery 8/25 in MX and had this too - developed 3 days after surgery - I was scared as it was red, swollen, painful and migrating up my arm. I went to our family doctor and he assured me it was just an inflammation and would resolve on it's own. AND, he assured me that it would not result in blood clots killing me - which was my main concern. Now I can still see a little bruising but no redness or pain. If you are concerned, see a doctor - it will put your mind at ease.....and if it is something, they can help!