What happened?

I'm not really sure what to think or feel here.  What happened is pretty simple.  I was at a bar and this woman came over and sat with me and started talking to me.  I really wasn't that into her, but she sure seemed to like me because all attempts to politely brush her off failed.  Next thing I know I'm waking up in her bed with a much worse hangover than what I would've expected from the amount I remember drinking.  Everything that happened between us talking and waking up is a complete blank.  I just got dressed and out of there as fast as I could.  I'm pretty sure we had sex that night.  I try not to think about it much, but it keeps popping up from time to time, especially when I meet someone new.