First people say its the hardest thing to do because it is. My god, you're 11 years old and you want a baby?? You probably don't even do the chores you're supposed to do at home let alone be responsible for a child. It's not like a doll that will be there to amuse you, something you can dress up and take out and show off and then put away when you're tired of playing with it. A child is a life long commitment, something that even someone twice your age isn't always ready for.
Second, they say it'll ruin your life because at your age it will. You want kids, thats great. But have them when you're a lot older and can afford them and give them the life they deserve. What have you experienced at 11? In a few years you'll be in high school and going on dates and hanging out with friends at parties or dances, just having fun being a kid. You think you'll be able to do that if you have a baby? You need a chance to grow and find out who you are, graduate from high school, go on to college if thats something you want, find a career in something you love to do. Fall in love because at 11 no matter what you think you don't know what love is. But don't have a baby now.
Yes, mothers do think that their children are the best thing thats happened to them, but don't you think that some of them wish they had done things differently and waited to have children? Been able to just be free and do whatever they wanted when they were young? I'm 21 and going to have a baby in 5 months and I know that i'm still not ready. I'm terrified, but that doesn't mean I won't love this child, it just means that if I had been smart I would have waited a lot longer.
You may not be put off at hearing it, but wait until you have to live it. And you're up at 3 am feeding the baby, only getting a few hours of sleep at night because its hungry or sick or fussy. You'll wish you had listened to everyone then and kept your legs closed until you were older.