All babies are different, which is something you will see after you have #2. After taking your son to the pediatrician to rule out any illness, just relax and enjoy the quiet time while it lasts!
We have a son, now 11, and a daughter, now 5. Our son went through spurts as a baby at the very same age as your son. He would just sleep and sleep...I would wake him to nurse and he'd fall asleep at the breast way before his feeding should have been over. He would then go through periods of being what the baby books made me think was "normal", then he'd have a spurt of sleeping all the time. I'd want to wake him up and play with him, and all he wanted to do was snooze!
Our daughter was born years later, and I never new how good I had it! She NEVER slept and still, to this day, operates fully on less sleep than any baby book author would ever imagine.
Your baby is an instinctual being. If there is nothing wrong with him according to your pede, let him sleep when he's tired, eat when he's hungry, and be awake when he's bright eyed and bushy tailed. Don't fight it. You'll be much happier!
Enjoy this time. Before you know it, you'll have girls calling your house for him. (Believe me...I know!)
Hugs,
J.