Dating scan question

​I just had my first dating scan, I found out I'm 11weeks pregnant, baby had a healthy heartbeat. We were given a DVD of pictures and a short video. I have watched this video over and over! The joy it brings to see my baby moving and kicking around in there. But I also noticed in all the video and pictures there is only 2 legs and 1 arm showing and moving. It made me worry my baby might be born without an arm. Am I just being paranoid or should I be concerned? Has anyone else had a scan like mine and can't see every limb?