Asleep on his belly? Where did my little newborn go? :(

This is the first time he's been asleep on his belly. When I was putting him to bed, I offered him a bottle and he kept spitting it out. So I just held him and rocked him for a couple of minutes. He placed his face into my neck....and then left it there. That was so strange as he's a constant moving being right now (like any 7 mth old). After a couple of minutes, I moved my head so I could see if he was actually asleep. He wasn't and just looked at me like I was crazy for moving my head and thus adjusting his comfortable spot :) So I looked straight ahead again and bam! his face went back into my neck again. It was quite sweet, but I knew he was sleepy, so I laid him down. 

....looking at the picture below, it makes sense! He just wanted his face up against something :) I wish I would have watched him turn over. Here lately he's rolled to his belly and fussed a little and then flipped back over. But this time he wanted to stay! :)