"we will see"

If you spoke to your fiance about marriage and all they can reply with was "we'll see" what does that mean? He gets kinda defensive when I bring up marriage and planning stuff. I'm starting to think he doesn't want to marry me and we have a baby on the way. I'm madly in love with him and I thought the feeling was mutual. I've been trying to plan little by little but that's the thing, it's me planning... Never him. Is this a red flag? I believe if someone wants to marry you they will, without a doubt... There shouldn't be a "we'll see".. We're in the process of moving into another apartment together and I'm not sure if I wanna even go through with it because of the whole "we'll see" thing now. It's making me feel like he isn't wanting to get married.