Sleeping thru the night!!

So a little while ago I started to supplement Aaron with formula. As my other post said, it was a tough decision, but he always seemed to be hungry, so I feel it was the right decision. Ever since I started, he's been happy and has been sleeping better. It took about a week and he was sleeping from 8ish until 3ish. That was a HUGE blessing as that meant only ONE night waking for me because he'd then sleep until about 7ish in the morning. Ahhhhh. Well, now I've started giving him just a tiny bit of rice cereal...like I said, the little guy constantly thinks he's starving, and he's eating it pretty well, so why not?!?! He has been so content, in fact, that he's been taking 80% of his naps in his crib (previously it was in his swing). I say 80% because often he'll wake after an hour from his afternoon (his longest) nap and I'll put him into the swing and he'll sleep longer that way. Well last night I put him down around 8:30pm and I woke up at 5am and he was STILL sleeping. Of course, being a mommy, instead of being thrilled, I'm concerned. So I got up to check on him. While I was using the potty before going into his room, I heard him. So I would officially consider 8:30pm-5am sleeping through the night! Great Job, Aaron. He's 4 months, 1 week and 4 days old. Not too shabby.