Glad to hear all is well with your son. I also wondered about hep b. I had to have it as an adult because I work with human and non-human cell culture and tissues...and the vaccine knocked me on my butt for a few days...much worse for a baby. Not really sure where a baby would pick it up unless they needed a transfusion.
My daughter is 11 weeks old today. She was doing all sorts of strange mimics from day one including smiling randomly when she slept. about 5 weeks ago she started smiling intentionally..now she laughs like crazy when something amuses her. She also really tries to communicate but only with my wife. With me she just laughs...probably the way it will be for the rest of my life
She also sticks her tongue out..for some reason, her favorite thing is if I stick my tongue out at her and yell blah!
That is really good that your son is pushing up. Does he enjoy it or does he get angry when you put him face down? My daughter hated it at first but now she can raise her head and look around and tries to crawl a bit so she enjoys it...but in general, if she cannot see my face or my wife, she gets upset....funny, that is exactly the opposite of my students