Was I wrong to not say “I love you”?

I’ve been dating my current boyfriend for 3 weeks and he told me that he loved me, and I don’t really feel that for him yet. I just don’t think I ~love~ him yet, so I didn’t say it back and he got mad at me. Was I wrong for not saying it back? I just thought it would be wrong to tell him I love him when I don’t feel that for him yet and I just think it’s too soon for me to say it. I’m 18 and he’s 21