I read on your profile you're 15?
I can understand loving kids. I babysit a few and they are very loving but having one comes with a lot of responsibility.
At 15, you're not finished developing so the health risks are just a start.
I noticed you said you want the baby, he wants the baby. What about the baby? I know a few girls who got pregnant early and wish it never happened. The guys that swore up and down to stay never did. It's a lot of work. It's giving up your money, life, happiness, chance at a future, having fun, going out, etc to take care of a baby day and night. Have you ever changed a diaper? Disgusting. You'd be doing that a million times a day/night. Babies scream, cry, throw fits in public or not they don't care. They need and want that's all they understand. You'd be raising a child then what would happen to the kid?
You're mom may say that now but I have a feeling she might end up being involved in it. Babies are a blessing when you're ready to settle down and in love with a man.