Lol my boyfriend does the same thing. my doctor said its ok to go to concerts while I'm pregnant so I'm guessing the bass in the car isn't bad for baby let him get it out of his system before the baby comes :) unless YOU really can't handle it then tell him to turn it down.
If it makes YOU nauseous then yes. Not medically but emotionally. Have you asked your bf to turn it down when you are with him? Does he just not care how it makes you feel?