Boyfriend problems.

So my boyfriend & I have been together for a year. I’m 21 & hes 25. He once told me that he wanted to marry me one day, have kids with me, live with me etc. & yeah we’ve fought, we’ve had problems, but we’re happy. But now he doesn’t even talk about marriage or anything. He even said that his thoughts on marriage changed & doesn’t believe that it’s necessary. He makes it very clear that he wants to spend the rest of his life with me, he tells me he wants a future with me, he wants to have kids with me, but he doesn’t believe in the whole signing a paper thing. I’m kind of wondering like why would he even tell me that in the first place if he was just gonna change his mind about marriage. I don’t know what to think anymore. What do you guys think I should do?