Osbourne was just 17-years-old when she first got tested and more recently she got tested while her boyfriend at the time was in hospital.
Speaking yesterday at Project Angel Food to commemorate World AIDS Day, she told E!Online: 'He was in the hospital getting his appendix taken out and they needed to test him and they were like, 'Why don't the both of you get tested?'
'They have amazing ways to be tested now. They had this thing that they just swabbed the inside of our cheeks with and within ten minutes they told us.'
Kelly didn't think she had the virus but thought it safer to get tested just incase.
She said: 'Now, it's something that is part of my yearly checkup with my doctor.'
The E! Fashion Police panelist added: 'When people say things like, 'It's never going to happen to me or I'll never get it,' they're less inclined to protect themselves the way that they should.
'It's so simple. All you have to do is wear a condom. It's not like anyone is asking you to do something really difficult and hard.'
Although the 26-year-old admitted she doesn't always have a condom on her at all times.
She said: 'I have condoms. But I'm not the kind of person who will go out with them because if I meet someone, it's not like I'm just going to have sex with him the first time we meet.'