Hun, it's normal to have "baby fever". And when you love someone, it's normal to want to rush in to everything. You feel like you'll spend forever together and so why not just get started on everything right now?!
But there's also common sense. Like the fact that it's very likely your relationship won't last forever, especially if he's older. And if your family isn't going to support you, it's probably not a good idea to have a baby. Don't you want your baby to have the love of an entire family? To have grandparents and aunts and uncles? What if your boyfriend leaves or something happens to him and you become a single mother? And you don't have the support of your family so what would you do? How would you balance a baby who's too young for daycare, school and a job good enough to pay for rent and a baby?
And of course your chances of getting pregnant are very high if you were ovulating. Why won't you use birth control? It's never a good idea to purposly get pregnant at 16. Wait another couple years until you're an adult hun. Get on birth control. Use a condom. Wait for a baby.