How many times was I invited to this party?

I was at a house party, in a house with many, many rooms. I think I had gone out somewhere and come back. I noticed (or perhaps remembered) now that there were at least two identical copies of myself hanging out in different rooms at the party.

I seemed to recall that the copies had been created only a short time ago, and that the copies are so exact that there's no distinguishable difference between us -- though I believe we are all wearing different colored shirts (I think mine was red).

I glanced into one room, saw a copy of me sitting on the floor with several other friends, talking and having a good time. I was okay with that, and moved on down the hallway.

At some point around then I felt like I was having a memory lapse, and I began to wonder again exactly which copy I was -- to be exact, I was under the impression that I was the "original", but then I thought I could vaguely remember some experience to the contrary. It bugged me a little, but not too much.