What is this in my belly?

So I've been feeling the baby moving for quite some time. Last week I was able to put Nathan's hand on my stomach and he was able feel her moving. But this weekend something bizarre, strange, and weird happened. I had the computer sitting on my lap while I was laying in the bed. I was peering over my bump and I was feeling the baby squirming... then out of the bottom of my eyes I start seeing my belly moving up and down. Wow! She was kicking or punching so hard that she was making my stomach move! I stared at my belly for 30 minutes in amazement. I wish I had the video camera to record it, but hopefully I will catch it on tape soon.