Trying to take my child

My fiancé and I got into it with his grandmother over something stupid so we left her house so we won’t have to be in the middle of the fighting and let things calm down now his mother is saying he’s going to end up in jail and we don’t deserve to have a baby “i am pregnant” and she says when I give birth she gonna get custody and take my child!

Update

My fiancé doesn’t care that his mom is making these threats and he says that I need to get over it, he doesn’t even care that she threatens to take our child