Anatomy scan

So I know I'm already having a boy from the harmony test, but yesterday I was supposed to have my anatomy scan and they had to reschedule it to Friday due to miscommunication. I'm kinda freaking out because I know this is the most important scan to have to see if their are any abnormalities or such with the baby. I had my uterus measured yesterday and the ob said it was right where it was supposed to and the heart beat was at a steady 144 , what are the chances of something going wrong ? I'm nervous ):