My household makes a lot of money. But there is no room in this house for me and a baby. 

My boyfriends house has a much lower income, and has a lot of room. I really want to move in with him. I don't want it to be weird though. So I wanted to sleep over to get kind of use to it since we are going to be parents together. My mom receives child support from my biological father. She absolutely does not want me to move out or sleep out at his house at all. Is she being selfish? There is no room in her house! Does she only want me to stay so she can receive her child support? I need to find a way to talk to my mom about this but she is very irrational. Advice anyone?