I can't seem to put my face to my body.?

I know that the face I see in the mirror is me, and I can recognize it as me but it doesn't feel like right somehow. I haven't lost weight and I haven't gained weight and nothing traumatic has happened to me. I just don't feel as if my face is really mine even though I know it is, or rather, should be.... I don't understand it so I was just seeing if it's happened to anyone else. It is an odd thing to try to explain but I tried.