should I tell my ex I'm pregnant?

My ex and I dated for almost 7 years but broke up about a year ago. We tried to remain friends for a little while but then decided it would be best if we didn't stay in contact. I met my current boyfriend a month after my ex and I stopped talking and ended up getting pregnant with my current boyfriend about 2-3 months into our relationship. I want to announce the pregnancy publicly but I'm so afraid my ex will find out somehow and try to cause problems although I'm hoping he'll just leave me alone. I'm starting to think maybe I should reach out to him and tell him myself? Then again I also feel like we are no longer in contact so is it really any of his business? I'm so confused and my hormones really aren't helping. Any advice?I appreciate all who take time out to read my post..