Black spot along side of my stitches.?

I had a vasectomy on Friday morning, it is now Sunday, and I just noticed this when I took a shower today. I have an incision on my right "side", its about a half an inch long with 3 stitches. Between two of the stitches, some the tissue is puffed up from the swelling, the rest of the skin around the incisions are the same, puffed up, but this one little section is black. I'm not sure if its just blood that's pooled up or bruising. I can touch it, it seems hard, but not painful to the touch. I've been using ice off and on up until last night, half an hour on hour off, then off during the night when I sleep. Since its Sunday the offices are closed until tomorrow. Just figured I'd ask to get an idea of what this could be so I don't sound too much of a panic when I call the doctor tomorrow about it if its still there or grows. Thanks