Need help protecting unborn child

Ok I am most likely the father to an unborn child and the mothers family has told me she is staying with her x again and he has thrown her against the wall and hit her stomach several times. He has always been violent towards her. She is hiding all this from me and it is a really weird situation but I am in fear of him hurting my unborn child. And apparantly I was told he thinks the baby is his. I know I can order a DNA test but my fear is him causing damage to baby especially when he finds out its mine cause most likely it is. He was just declared by court unfit to be around any child. What do I do. There is more to this story but my main question was stated.