Black thing coming out of incision?

Hi all. On Friday evening I had vaser lipo to the abs and flanks. I'm still in pain but have been able to get to work yesterday and today.when I got home this evening I removed my compression garment to wash and one of the incision patches fell off. When I looked it seemed as though there was a black string like thing coming out of it! I pulled it thinking it was hair but it wouldn't budge so I just put a plaster on it and left it. What could it be? I've been worried it was a vein or blood vessel or something!! :O please help