Hurt baby??

I was holding my baby tonight who is 4 weeks old and he projectile vomits which caused a jerk response from me because it surprised me and baby vomited/spit up a ton and was crying. My husband said he was worried about our baby’s brain the way I jerked. His neck was supported so I would have never thought baby could be hurt until he says that and I have been bawling ever since worried I have hurt our baby and caused him brain damage.,. What do you all think? After he realized he made me feel awful he said he didn’t think I did but I needed to be more careful which I agree but it was a “knee jerk response”. But do you all think baby could be hurt? He hasn’t acted strangely and he sleeps a lot anyways being a newborn. I’m just terrified I could have hurt him. We have his one month checkup in the morning so of course I’ll ask the dr too.