Why do you say that everyone has the right to decide over their own body? That is not true in real life. For example, I am not allowed to go out with boys or have sex until I am married. It would make my family very angry.
Sometimes, your family, relatives or other adults don't follow the law. They might not know what rights you have as a young person. Or they might not care about your rights. Some adults think they're doing what's best for you, even if what they're doing is wrong. In such case, you might not get to do what you have the right to do.
The right to decide over your own body is a right that everyone should have. I can understand that you might find it strange to say that everyone has these rights. A lot of young people feel like they don't get to decide over their own body. But, according to Swedish law, you always have the right to do this.
On Youmo.se, we want to inform you about your rights and the laws that exist in Sweden. The adults who are responsible for you should make sure that you get what you are entitled to. If not, you have the right to get support and protection. You can get this at places like school, a youth guidance centre (called ungdomsmottagning in Swedish), Social Services, or an organisation that works to help young people in the same kind of situation as you.