Growing Sleep?!?

Jack's last feeding was 4 oz. at 5:45pm.
He then spent some time playing with his dad, then tuckered out around 8:30pm.
It is now 12:36am and he is still asleep.

I can hear him fidgetting around a bit via the monitor every now and then, but for the most part, he's been sleeping - like a champ!

He's done this before...sleeping a bit longer and having a longer duration between feedings. The last time he did this, I woke him up promptly 6 hours after his last meal as I was worried he was sleeping through his meal for no good reason.

During his 2 month well baby check up with our doctor, when I mentioned that I had to wake him up for a feeding, she assured me it would be okay to let him sleep through to his content.

"Really?" I asked in shock.
"As long as he's continuing to grow normally - which he is - just let him sleep through. Babies grow in their sleep."

Apparently, they go through cycles where it seems all they do is sleep, and cycles when it seems all they do all day is eat like there's no tomorrow. Jack's done both. He's up to 4oz feedings regularly now. We also don't have to burp him every ounce any more. We are down to two burps - one at the half way mark, and the last after he's finished - which has been up to at 5.5oz at one point. Jeesh!

Even with our doctor's encouraging and assuring words, I am still a bit worried that he's sleeping so long. He better be growing and getting stronger. We have a big day for him tomorrow. A bath, grocery shopping and Babies R Us!