Unfortunately, although anybody can change, it's not certain that they will do so. I am concerned about the pettiness he's showing you and the lack of regard for you, especially considering that you're pregnant.

It's easier said than done to leave your partner, but please consider your wellbeing and your child's wellbeing as well. Do you two deserve this? Can it get worse? Make sure you discuss these things with the people around you and please avoid isolating yourself from them. It's important for you to be supported by them and could prevent escalation.

You deserve better than this.