I have the shaking/shivering thing, too, and vaguely remembered reading it was normal but sometimes got a bit worried over it so I'm glad someone else asked about it! I sometimes second-guess myself a bit, too, at appointments when they ask how the baby is moving, and I always say he moves plenty because that's how it seems to me, but still, this is my first baby, what do I know? But I've also grown so used to kicks and rolls and elbows that I don't even fully notice them all anymore, and sometimes my husband will have his hand on my stomach and he will jump as the baby does some strong movement that I've barely noticed.
I was at a party last night and some people I don't know showed up with their 4 day old son. He was born at 37 weeks and only weighed 5lbs and he was ridiculously tiny. It was a bit terrifying, actually, thinking that my baby is only like a pound or so smaller. He was very sweet and slept the whole time, though, and my husband and I talked about how impressed we were that they were out and about 4 days after giving birth. One of my friends at the party is Korean and we talked about how for her, mothers aren't expected to leave the house at all for the first 21 days, and everyone else comes to you. Sounds sort of nice in a way, but I think I need to leave the house more often than that or I'd go a little crazy.