What should I do??

My boyfriend and I have only been dating for six months. However, I like to talk about our future and would like to know what he wants 3 years from now or 4 years from now depending on if we are still still together. He's the type of guy who doesn't like talking about the past or when he has done cute things for me. He considers talking about stuff like that too "girly". I know we are not ready for kids yet but whenever I bring up the subject of having kids in the future he gets mad and won't even tell me if he plans on having them or not. It's a big thing for me because I definitely want kids in the future but he is giving me no answers. I don't know what to do..