Feeling the baby move?

I’m 11 weeks today, but yesterday in my way home from work I felt this strong kick or flutter about 2 inches under my belly button. It was much stronger than those little gas popping feelings you’ll get every now and then. It startled me and made me jump. Did I feel the baby kick or was it really just gas? This is my first pregnancy, I don’t even have a baby bump yet but I can feel my belly getting harder.