is wanting a baby a hormone problem or just being a girl

I'm 18 in college and I am like crazy on baby fever! I think of a family everyday I have baby names picked out and everything! I'm not pregnant I'm on the pill and have safe sex I'm not ready to have a baby and I won't trap my boyfriend because we both have goals and I want him to achieve them but how do I stop thinking about having a baby is it a hormone thing? Am I just nuts?!