June 19, 2012 14:47 IST
The reality TV star had been dating her boyfriend at the time for two years and decided she wanted to lose her virginity to him, so her mum Kris Jenner
decided she needed to take precautions so agreed for her to go on the contraceptive pill.
Kim - who is currently dating rapper Kanye West - told Oprah Winfrey: "When I did want to have sex the first time I was almost 15. I said to my mom, 'I think I'm going to, or I want to', and she was like, 'OK, so this is what we're gonna do, we're gonna put you on birth control.' She was, like, really open and honest with me."
Kim has become famous for her love life and in 2007 a sex tape featuring her and then-boyfriend Ray J was leaked onto the internet and eventually released as a DVD and
while she admits it was hard to deal with at the time, she knows it helped propel her to stardom.
She said: "That's pretty much how I was introduced to the world. It was a negative way, so I feel like I had to work ten times harder to get people to see the real me."
The 31-year-old socialite has starred in several hit reality TV shows - including Keeping Up with the Kardashians, which she appears in with her mother and sisters Kourtney and Khloe - and has a number of business interests including her own signature fragrance.