Rolling over

A few days before he turned 4 months, he rolled over! Back to front! So odd as so early, and usually they roll over front to back first! As it was so early his rolling is sporadic and Mike hasn't even witnessed it yet.  I've seen it happen a dozen times or so.  And last night when he woke up at 4:30 he was on his stomach when I went into his room.  So he's doing it, just not the rolling you get when they're older, like during diaper changes.  I need to get a picture or video of it....