Sleeping on your left side supposedly increases the circulation to the baby, but it wasn't natural for me, so it makes me a bit sore sometimes. So every morning when I wake up, I flip over to my right to balance it out for a few minutes.
And every morning, Abbott flops around in there when I do. He's only moving around periodically these days, but I can count on him moving around at that moment. It always puts me in a wonderful mood. And I say to him, "Good morning, Abbott!" And then I know it's going to be one.