The first time 'Jenny' was paid for sex, she was 18.

It was in a stranger's car, in a lay-by.

Around a year later, as a university student, she decided to "take it seriously" and signed up for an escort website.

Now 22 years old, Jenny still chooses to earn a living by having sex with strangers, but she says she is "always on her guard" whenever she is with a client.

Jenny agreed to tell her story of life as a student sex worker if we didn't use her real name.

The biggest ever study looking into the issue has been published.

One in 20 students who took part said they had worked in the sex industry.

That includes things like glamour modelling and web-cam modelling, stripping and prostitution.

"I don't think I had any positive influences that drove me to do it," Jenny told us.

"I just thought, I've got nothing to lose. If I find it degrading I won't do it, but I didn't and yeah I got a taste of the good life.

"My rent was so expensive and I didn't want to ask my parents for money."

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Although Jenny calls it the "good life", she said she was aware of the risks of having sex with strangers.

"I'm not scared of men [but] I don't trust them. I'm always on guard."

Jenny admits to being "terrified" that first time, and feeling "unsafe" at times since then, but she adds "I've never feared for my life."

"They've (clients) got feedback on the site I use from other escorts. Some of them don't and in that case I will not see them.

"Sometimes they just feel a bit dodgy and I'll keep my bag close to me and get out as soon as I can.

"The majority of the time it's completely safe, it's fine." she says.

"A lot of men are physically bigger and stronger than me. I'm not going to assume they're going to hold me down and force me to do things I don't want.

"I never feel like they're going to rape me or anything."

My rent was so expensive. I didn't want to ask my parents for money

Prostitution laws in the UK are complicated. It is legal for two adults to agree to swap money for sex, but things like running a brothel, advertising sex services or encouraging another person to sell sex are illegal.

Jenny says she has lost count of the number of men she's slept with. It could be anywhere "between 300 and 1,000".

She says she knows of the health risks that come with sleeping with so many people.

"I get tested every three months, I never have unprotected sex with them [the clients], I get offers but it's not worth it."

Jenny thinks that, like it was for her, money is the motivating factor for most students who work in the sex industry.

"Sex is becoming more accepted by society.

"You can earn big amount of money quick. I think some girls just see it as an easy option."

Help on sexual health and relationships is available at on at BBC Advice

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