It's natural to want a baby at a young age.
I went through it at age 15.
I was in a very serious relationship and I of course, did my fantasizing.
Although, I got over it VERY quickly.
I did a lot of research and found the costs of child birth, clothes, food, diapers, furniture, and other baby necessitys and I think I almost had a heart attack.
So before you make any rash decisions, I would research until there's nothing else to research.
And, wait until you're madly in love, and you're done with college/ or have a stable career, whatever you're shooting to do, get married, and then save a decent amount of money and set it aside just for your baby/ family together.
It's what's best for you, the guy you may be involved with, and your future children.
Good luck, if you need to talk,
PM me.