OP, I'm going to believe you're genuine. I don't doubt how badly you want a baby. I've known my whole life I want to be a mother. By the time I was sixteen I wanted a baby desperately. If I'd had a boyfriend at the time, I probably would have rushed into a marriage and baby as fast as I could. My mother had my brother at age 20 (married and planned) and I believed this was a 'deadline', I wanted to be a young mother, I wanted to have a baby by then.
I'm glad I didn't. I decided instead to spend my time training as a teacher. I love it. I work with small children and my career and continuing education is fantastic. The desire for a baby is still there, the monthly tears when my period comes on (even though we have protected sex) - I still hope I accidentally fell, but I move on and I'm glad every month when I haven't.
I'm 22 now. I have a stable partner of several years. We live together. We both want children. We still are not trying. We've only lived together a short period, though we nearly always slept at each others' before. It is vastly different.
All of life changes with a baby. Much of it is good. But there is so much you will not experience the same way if you have a child. Getting to know my partner, living with him, would be entirely different if we had a baby or a pregnancy in the middle. My education and career choices would change. It doesn't seem this way, but your way of thinking and life experiences will change so much in the next few years. I am not the same person I was at 18.
I still plan on being a young mother, I want to have my babies before thirty, and I have a solid life plan toward that (if all goes well with ttc). But if I followed my teenage way of thinking, I would have none of it.
Think about it, OP. Consider giving yourself a year or two, see where you are then. Babies are wonderful, I love them, I want them, but there's a difference between wanting a baby and knowing you can give them the best possible life. It has to be for them, not for you.