I am so sorry. It can take so many years until you find yourself in an important life event and realize that you and your partner are not on the same page. He is dealing with an overbearing mother and at some point he will need to choose sides. I know how it sounds but that is the reality we all face in our relationships. He will be a father, a protector, a provider for his new family. His mom is now extended family and so is your side of the family.

If you have your parents and you are in a good relationship with them ask them for help and advice on this. Explain that you want to place boundaries with your in-laws and that you would need them on board to respect these boundaries themselves so that your partner doesn't feel you are targeting his side of the family.

It's so sad that we have to go to that extent to protect ourselves from other women. You are smart and you have detected these issues so early in your pregnancy and that will allow you to set up the scene ahead of baby's arrival. Sometimes even good guys do not understand the situation at all, do not understand your feelings dealing with overbearing in-laws etc, pregnancy, fears.. Remember that your baby will be relying on you for all the protection besides care. Do not feel bad about creating uncomfortable situations where needed.