Depends entirely on what time of day I notice it. If it was right off the bat, after waking up, I'd most likely not react at all, as I'm a zombie-like creature until around 11. After that however I'd call the police, then moan about the clothes it ruined afterwards.
My initial reaction would be something along the lines of,screaming, wetting myself, and vomiting, not necessarily in that order. And then because I have never been one to waste resources my second reaction would be "Who wants soup."
I kid of course I would never make soup out of people. Human meat is much better suited to sandwiches.