I've never experienced this before, but I have read of other people going through it. I know Kacee had an accident or two after she was spayed, but that was it. She never did again. Since it has only been two weeks since she was spayed, then perhaps that is it. Personally, I'm inclined to think she is trying to tell you something...like she wants attention instead of you working. They are attention hogs, you know?
