Well, i never thought i would say this, but i really wanna have a baby. im 15,?

well, i never thought i would say this, but i really wanna have a baby. im 15, & i got a boyfriend, but the thing is he says he isnt ready yet.. but, he said if i do get pregnant with his baby, he will stand by my side and support me and play his role. i dont wanna have a baby with someone else, i wanna have a baby with him, but how?