I am very very troubled by his violent behavior, rockstar, and I just can't offer encouragement to you, though I do understand so much your wanting to give it one more try because he is using different WORDS right now.
But because he is exhibiting violent behavior, I just cannot support your decision to allow him back into your home and to stand by him as he tries--according to HIS rules--to stay sober.
My belief is that he has just bought himself a get out of jail free ticket and that when he does drink again--which will probably be shortly--he will be more violent and angry than ever. And you will again be traumatized and possibly assaulted. These erratic shots of incredible trauma and stress are threatening your baby's health, you know that, don't you?
So if I could wave a magic wand, I would ask you to separate yourself from him, go stay with a friend or family member for the remainder of your pregnancy, keep your cell phone on you at all times in case he shows up mean and drunk, and do not have ANY kind of relationship with him UNTIL he has ONE CONTINUOUS YEAR of SOBRIETY AND GOOD BEHAVIOR.
Do take care. I know you are trying. When your newborn begins crying through the night, if he is in the house, I can pretty much predict he is going to lose it.
I'm so sorry for your situation. Please rely on those who love you. (Unfortunately that does not include him, as long as he puts the drug ahead of you).