Swelling under arm

Hi -I had a lumpectomy ten days ago with auxiliary clearance of lymph nodes. First few days were a breeze, no pain just some colourful bruising but I now have a swelling around the scar under my arm, which is visible from the front, also pain (to touch) down the underside of my arm (I’m assuming nerve pain?).  The swelling is really sore and resting my arm against my body isn’t comfortable at all.  Has anyone had this, is it normal? I don’t think it’s a seroma as it’s not fluidy.  I was planning to do a couple of weeks work in August but now thinking sitting on a computer my not be such a good plan.  Any support/advice welcome 

It may still be a seroma , mine felt quite solid , it was around my sentinel node scar and was extremely uncomfortable . I had it drained but it filled up again , eventually it disappeared almost overnight .Best ring your BC nurse and ask them to look at it . I found the healing under arm a lot more tricky than from lumpectomy itself .Best wishes Jill