You really want to spend your life on tenterhooks, wondering when he'll snap again?
Was he right to be at least a little bit angry? Maybe a tiny bit. But that does not justify him hurting you.
Period, end of story.
Get out before you are even more committed and entrenched.
Get out before he lies to you that it will never happen again.
I urge you to protect yourself and your unborn child. Call your parents and ask to come back. Explain what happened, pack your bags, and leave.