Lying on your stomach

Talitha
So, I'm sure everything is fine, but today in yoga we did a very gentle stretch where we were lying face down and raising up our arms. Since I'm only 12 weeks, I didn't think it would really matter but I felt some weird fluttering around my uterus when I got up! I wonder if it was uncomfortable for the baby...I'm just hoping I didn't actually hurt it! :/