Sarah will speak at a sexual health conference on Thursday

I feel very frustrated that my friends don't know what I know. My mum is a nurse at a sexual health clinic. She has always talked to me and my sister - who is now 21 - about sex and relationships, but also about what can happen if you have sex without protecting yourself.

Mum told me once about a girl the same age as me who'd got a disease from having sex, and she told my mum she didn't enjoy doing it. Mum asked her why she didn't just say no - the girl said that she didn't have 'a because'.

I'm lucky because my mum has given me a because. I don't want to have sex yet because I don't want to pick up an infection. One day when I'm older, I will want to have sex, but I'll know how to protect myself.

LETS TALK ABOUT SEX Children who talk openly with their parents wait longer And when they do, they're more likely to have safe sex British teens are most likely to talk to a friend if planning on having sex But those in Holland - which has a low teen pregnancy rate - talk to their parents Teenage Pregnancy Unit research

But how do people my age get their because? From talking to their mum and dad.

Parents should try to be open and positive. If your kid gets embarrassed and doesn't want to talk about it anymore, say 'it's not embarrassing, how do you think you came into the world?'

Some of my friends don't tell their parents that they've got boyfriends because they think they'll over-react and judge them. It would help if parents trusted their kids - be on their side no matter what they tell you. If my mum can trust me, then I can trust myself to make the right decisions.

Information for all

When I was little I used to carry this body book around with me everywhere. My grandma used to dread it because I would always ask questions. She was very proper and didn't like talking about bodies and relationships - and quite often she didn't know the answer. That's the problem with some parents too; they worry that they just won't know the answers.

Teenage sex is tackled on soaps

There's loads of information available, but not everyone wants to pick up leaflets or search online. So I think one way to get this information across could be TV, because almost everyone watches TV.

People in soaps are constantly shown to be sexually active, but rarely do they show what can happen. Yes, Sonia in EastEnders got pregnant, but even Janine isn't shown catching diseases. Is that true in real life?

They should have a storyline in Holby City where a character finds out she's sterile from a disease she picked up from having sex at a young age. That might get people talking.

I wish we could talk about these things more at school. Some adults say that if you talk to young people about sex, then you're encouraging them to do it. But if we don't have the information on the dangers of unprotected sex, then how will we know?

This doesn't only have to be in sex education. In history lessons, we could talk about the kings and queens with syphilis; in biology we could look at the bacteria and viruses that make people ill.