why is baby on different sides of uterus?

Au
I'm sorry if this is a stupid question. I go in for my NT ultrasound next Wednesday but I was curious to hear from my fellow glow ladies. Most of the time when someone posts a pic of their scan i have no clue what I'm looking at. 
Is it possible that they just took it at a different angle? 
First US was vaginal and at 7 weeks. I even saw the flickering of the heart beat.
Second US was done at 9 weeks and I could hear the heart beat.