My baby rolled over!

I can't believe it! Yesterday morning he rolled from his back to his tummy, but he was laying next to me on my bed, so I thought that it was more of a fluke since he kind of rolled down hill. Then yesterday afternoon I went to pick him up from his crib, and he was laying on his tummy! I know that I laid him down on his back! I can't believe that he is such a big boy all ready! Before I know it, he is going to be sitting up on his own! Wow time flies! It kind of makes me sad. I miss him being a little baby, not that he was ever really that small! :)