well, an old wives tale would dictate that you are having a girl. :-)
My dd's heartrate was consistantly between 170 and 160 my whole pregnancy.
Keep in mind they baby responds to YOUR stress as well. I can imagine that beening set up in a hospital or doctors office, amxiously waiting to see if my baby was ok would stress me out even just a little, and so your babe was probably just responding to you as well.
Silly story: we went in for an ultra sound with this one last week and I was so excited to learn the sex, I could tell I was a little amped up. Well, when they did the heart rate on my little guy, he was up to 160! He has been between 130 and 150 for my entire pregnancy....and I think he was just reacting to mama. When I am at my wonderful midwives place, in the cozy room, the heartrate is ALLLLLWAYS lower, and I think it's because I am more relaxed.
Anyways, that doesn't sound especially high to me and maybe you might want to get a fetoscope and see if you can check yourself when you are relaxed.