pulsing belly..am I crazy?!

I'm exactly 11 weeks today and when  I laid down to rest, I swear my belly had a fast/rhythmic beat that was different from my heart rate! I thought I felt this yesterday too but shrugged it off but today I know I felt something for sure. I looked it up and saw people saying this is the baby practicing breathing but those moms were all 30+ weeks and I'm only 11 weeks! Does anyone know anything about this or experiencing this too??