Does she think I had sex with someone else?

[Andrew]

I asked the girl I like to go out clubbing with him on a Friday night. I told her I would be in the city for the night and she was trying to surprise him. So she said she would think about it and she came. When she asked me where I was, I said I was at his friend's house and they were playing computer games. Few days latter, my friend uploaded photos of me with another girl in a nightclub on facebook. Now she is not answering my calls.