The Girls Aloud singer - who recently admitted to only ever being in two serious relationships - felt under pressure to lose her virginity, but refused to give in to her friends.
She said: "As a teenager I felt the pressure to have sex to an extent where I felt like, 'Oh God, maybe I should have done it by now.'"
"But it was never strong enough to make me feel like I should act on it. I was quite headstrong about sex and knew it wasn't something I was going to give away easily. Sex should be with someone you really like, so I refused to be forced by peer pressure. Sex is a scary thing - you've got to wait for it to feel right."
The 28-year-old pop star - who has been in a relationship with boyfriend Justin Scott for around seven years - also claims sex should never be the most important aspect of a relationship, just another part of it.
She added in an interview with More! magazine: "Of course it's important but it's not the be-all and end-all. There are other things that are more important for a long-term relationship."
