Hi
@Ana Sofia
Condoms can be safe and they're a good protection against sexually transmitted diseases (Google them - there are some horrible diseases so always use a condom) but they're not 100% effective. That means you run the risk of pregnancy and possibly catching a sexually transmitted disease.
There is no reason why a girl of 16 couldn't take the Pill but you would need to speak to a doctor and make sure it's suitable for you. A doctor would also decide which kind of Pill was best for you. If you do take the Pill, it's important to take it exactly as the doctor tells you.
You could see if there is any organisation in your country that offers free contraceptive advice to young people.
It's good you spoke to your mum. you haven't said why she doesn't want you to take the Pill. If it's because of health fears, then perhaps a check from your doctor will help your mum relax more. If she has other reasons, then talking to her is always a good thing. I'm sure she wants you to be safe and happy in your life.
So - quick answer. Condoms are not 100% protection. Speak to a doctor or nurse about more contraceptive help and also to get indormation about sexually transmitted diseases and how to protect yourself.
And remember that YOU are in control. Never do anything you don't feel happy doing. The most mature teenagers are the ones who understand that it's sometimes best to simply say No.