OP, please please PLEASE double check everything your partner is telling you!! Especially since he got mad that you didn’t believe him!!

This genuinely sounds like he wants to move back to his family and thinks that he can “trap” you in a terrible position where you would be unable to fully communicate with the hospital staff as you give birth, never mind with clearing this up with the government paperwork if you DID give birth over there... and not to mention that English isn’t even the primary language at all, is it? I would expect it’s Spanish because, you know, it’s Mexico. Are you supposed to rely on your husband or his family to translate the entire time, or magically become completely fluent outside of the lessons you’ve had?? I know you would probably pick it up quickly because of language immersion and all that, but that’s not the point.

I sincerely believe your husband is lying and trying to trick you, OP, so please take care of yourself and your unborn child. I’m not one to suggest ultimatums, but unless he can give you an honest answer without changing his reasoning as to why he wants you give birth to your child in Mexico... perhaps it’s time to start looking into separate finances at the very least, so you have something to fall back on that isn’t related to him.