I am currently 28 weeks pregnant and I had my ultrasound dating scan on February 18, 2011, which said I ovulat?

between December 17, 2010 and December 21, 2010. I am in a monogamous relationship, but I went out with my girlfriends on the night of December 17, 2010. There was a creepy guy at the bar that kept hitting on me, but I repelled his advances and kept it cool between us. He did follow me around all night though. I got a little tipsy and remember all of that night... at least I think. I had a very scary dream in my first trimester about this man that made me feel uncomfortable. I dreamed he raped me in the women's bathroom of the bar that night. I woke up crying and asked the girls I waswith that night if I was ever left alone with him, and they all said no. I am truly paranoid that I blacked out and had sex with this guy in the bathroom on that busy bar night, but I realize that it may be just a dream. I had no bruising or anyting the next morning, and never doubted my baby's paternity until the ultrasound conception dating put my mind intpo a tailspin of fear. Is it possible that he raped me and I just did not remember it but dreamed of the event later in my pregnancy? Please help me, I am so scared.