In my opinion it sounds so beautiful that you love little kids and that you would give up everything to become a mom. I don't see anything evil or that you could be referred as a bad person, however, unfortunately I have to agree with other and tell you that you should wait with your decisions... I understand that you may not like to hear it but it is true and there's nothing you can do about it, no one can. I also wanted a baby when I was in my teens and as you I was thinking about it seriously but I got friends older than me and they explained that I should not have a baby in my age and sincerely I am very glad now that I followed their advices. I also was in a wonderful relationship with a really nice guy and I thought that he will be the daddy to my children and my husband, however things do change out of nowhere and you don't know what life prepared for you. I don't want to say that you won't marry your boyfriend or that he won't be the father to your kids, I actually wish you this and I really hope that this is going to happen because this is very beautiful! But even so I need to tell you that you should reconsider your choice. You and your boyfriend are going to go through many many wonderful things together and it doesn't matter whether you truly love each other, you will miss these steps if you're going to get pregnant now! Believe me, you still need to find out each other! You need to create events together such as spending time together and fooling around doing whatever you want, traveling together, going to clubs, even spending time together in bathroom and many many other activities. Having a baby now you will miss so much in your life! You may think that these are only ""foolish"" things but trust me they are not, you need them, everyone needs such moments near they loved ones because it connects you as a couple so you can do the rest of your life plans including a baby and other serious steps TOGETHER! Take these wonderful teen years to get to know each other and be together by yourselves! You should and you have to do so much things before having a baby! I only wish you that you will love each other for the rest of your lives and I said that you have to do these things if you're going to be together, but imagine yourself if this won't happen, what then?
Now I'm together 8 years with my husband and we're married for 3 years and trust me so much things changed since then! Since we got married so many "little" things disappeared but sometimes I miss them so much! We love each other, everything is fine and I'm very happy near him! But I want to say that many things are going to change! I didn't know even a half of what I know about him now! I'm still nowadays discovering him. You may not believe me but this is the truth. There's no other thing I am surer that he is my soul mate, I am sure that he would do anything for me and for our family, I am up to do the same, however we still have fights and misunderstandings. Despite this I know that I will be with him and it doesn't matter what is going to happen I will love him. All this is due to the fact that we have been thru so much situations together!
Besides your relationship with him you have to think about many other things that were mentioned above by other posters! You should make sacrifices for kids just by being there and spending your time, but you also would need knowledge and a job for making money, you will need to have life experience! Everything is just to become a good parent and that one day your children will call you the best parent ever! Only loving your children is not enough! Moreover you have to talk to him about this very seriously, you should make such a serious decision together! However you should live your life a little bit! I'm not telling you that you should wait until you're 25 or 30 years old to have a baby, but wait at until you're going to be engaged and to be able to take care of your own not depending on your parents with anything. Wait until you're going to be ready emotionally and financially! Both of you should taste a little bit what is life then to give life.