That would be the baby. At 26-28 weeks I was even able to see it when laying on my back. To me laying on my back is when I feel him the most.
It will be a little hard to distinguish right now. The baby is still so small, but around 22-25 weeks you should be able to feel the baby make thuds, and taps at random areas of your tummy.
I think gas might be more uncomfortable . Lol this is my second pregnancy when I feel baby move it feels like baby is tap dancing on my private part