I have to say, I read this backwards at first. For a split second I thought you said Nanosex while pregnant. I thought, I've heard of a quickie, but never nanosex. Ha! Anyways what's done is done, so don't stress about it. I am sure there are hundreds of women that have done things they shouldn't have before they found out they were pregnant.
Personally, I went out and drank myself stupid on New Years eve when I was pregnant. When I missed my period at the end of January and found out I was pregnant, they did an ultra sound. I figured I was just a couple weeks along, in fact my period stopped the day before New Years, normal cycle and all. Nope, I was six weeks along. I just had a normal period while pregnant. I was horrified and told my doc about the night out, and she said one night this early in the pregnancy isn't anything to worry about.
I couldn't change what had happened, so I just prayed for the best. My daughter is now an exceptionally bright 3 1/2 year old.