How long to wait to tell ex and his family about the pregnancy?

First off. i hate him. with a passion. He has gone out of his way to absolutely ruin my life in the last year and I honestly never want to see his face again. But I won't deny him his child. I would like to wait until I'm in my second trimester.. because I had a miscarriage 2 years ago, and he accused me of lying about the pregnancy, and that hurt a lot. So I want to wait until the risk of miscarriage goes down.. I don't know how to tell him either, he has a new girlfriend now and I know it's going to cause a lot of drama, and his mom and I left on bad terms so I know she's gonna be a down-right bitchh about it and try to control the entire situation..... any advice?