The Californian model was rushed to hospital with a mystery life-threatening illness two weeks ago.
And now it can be revealed she suffered an ectopic pregnancy after a raunchy sex session with house-mate lover Steven Goode.
But Kimberly, 23, has been told her baby had no chance of survival due to the severe medical complications. And now she fears she may never be able to have children.
Kim enjoyed an X-rated romance with Steven, also 23, on the Channel 5 show.
Millions of fans saw them having a sex session in the bedroom while the other housemates slept.
But the joy turned to heartache when the former bunny girl was rushed to hospital suffering from severe stomach pains.
“The doctor has said that there’s a chance I won’t be able to have children”
Kimberly Kisselovich
Speaking exclusively to the Daily Star, Kimberly said the couple had used protection during their BB romps but “the condom split”.
She added: “In the past 24 hours I’ve had a diagnosis from the doctor and he’s sure that I have had an ectopic pregnancy.
“That’s why I had so much pain in my pelvic area which I thought was an infection.
“The doctor said that with the time frame it was definitely Steven’s.
“I’m really concerned. Steven’s speaking to all the doctors – he’s really upset.”
An ectopic pregnancy is when a fertilised egg starts to develop outside the womb.
Medics have warned that she may now need surgery to remove the egg from her fallopian tube.
The heartbroken babe added: “The doctor has said that there’s a chance I won’t be able to have children.
“I’m trying to keep positive because we don’t know for certain.”