My suggestion is if you call and make this contact that you do not share it. Just for your safety. In some cultures, women are treated very badly, sometimes they are made to leave the home while the children stay, etc. and we don't want that to happen to you. I would keep your 'escape' route to yourself until the last minute for your protection. Let us know what the crisis center says. We'll be thinking of you. This sounds like an intolerable situation and you sound like a smart women who knows this can't go on. Anniebrooke did a great job providing a crisis place for you to contact! Let us know how it goes!
I would make sure your spouse knows how you’re feeling and how serious your feelings are and if he does not care then I would try to compile your resources and be separated if not divorced.
If you are in a traditionalist country, what are your options? Some are more strict on issues like divorce than others. I would certainly not put up with being the person whose happiness and sanity is sacrificed for the in-laws who are horrible to me, especially when pregnant! But I am in the U.S. where a woman (even one who is pregnant) can walk out on an unhappy situation and there is little social stigma. (In fact, there is sympathy and some support if she can find it, such as women's shelters.) Your mentioning Umraah makes me feel less able to offer you intelligent suggestions because I don't know what is culturally acceptable for you. That said, however, your choice of leave or die, means you must leave. Do not die over people who are not worth it. Your duty to your child trumps your duty to any other family member.