What would you do?

So, about a month ago I hit the lottery.. my boyfriend became enraged that I bought a home and a car for myself and my children (he wanted to quit his job and do nothing and I think he enjoyed everything being in his name) I wanted security and for things to be mine and my children's. this became a blow up fight and I saw a part of him that I never want to see again, so we left. he had always shown signs of being possessive and hateful but I didn't have anything and he didn't want me to have a job or anything. our last fight, he said major hurtful things about me and my kids and I never want to see him again.... that was a month ago, I just got a positive pregnacy test.... I don't want to tell him because the last month he has been borderline crazy with his begging and threats. my Mom says I should tell him when 'he calms down'. I'm fine with not telling him. I'm mostly afraid that he'll hurt the baby or use them as a pawn... I don't think I should tell him... should I?