Re: nipple chomping...
My son got his first 2 teeth at 4 mo. as well and did the same thing. At the time I was just sure there was no way he could comprehend that he was hurting me, but I read to still say sternly, "No, no, hurt mommy." and take the boob away for a while. After a while he stopped doing it, but I never knew if he actually understood or if he just stopped needing to bite something. He got his next two teeth at 6 mo. and that was a much easier time. I never scared him or anything, but I've heard you have to be sensitive not to scare them into a nursing strike. All he did was pull off and look and laugh at me.
Good luck! He drew blood a few times and I got VERY frustrated, but it was only a phase, and this too shall pass!!
Emily, mommy to
Jeremija Charles - 5/30/07 - nursed 26 mo, and
Aleksandar Hayes - 12/13/09 - nursing strong!
"Forget past mistakes. Forget failures. Forget everything except what you are going to do now and do it." - William Durant
If you really want to do something, you'll find a way, if you don't, you'll find an excuse.