Okay, what's the question or problem? Or did you just need to get that off your chest? You'll have no problem having a baby one day. Best bet would be in vitro fertilization. You would pick a donor, and use his sperm, and they would use your eggs. Then implant the fertilized eggs into your uterus. Don't worry or be sad about it. Get through your young life and when you're ready for a baby, you can look into it.
20 is good. That's up to you. I would recommend college (uni), and getting yourself ready financially first. And being in a loving, commited relationship. Where both of you want a child and can go through all of it together.
I had my first child at 14, I adore my son, don't get me wrong, but I was not ready. At 14, you deserve to shop, have crushes, etc, etc. And btw, at 16 I was convinced I was through with guys since I couldn't be with my boyfriend, that I was a lesbian, well turns out i'm not, I do have feelings for women, but I am in a happy relationship again with my fiance.