CHICAGO -- Christine went to a Chicago hospital in 2013 after she was raped. She had gone out for a night of dinner and drinks with friends, and said she does not remember the attack itself.

"I don't remember anything after leaving the dinner portion," Christine told CBS Chicago. "I woke up naked and I don't remember anything else after that."

Christine is thinking of moving away from Illinois, to get away from memories of her own rape, and the nightmare she experienced afterwards, when the hospital demanded she pay for her rape kit.

Get Breaking News Delivered to Your Inbox

Illinois is one of 13 states where rape victims often have to pay for their medical bills after they've been attacked, including the kits used to collect physical evidence of the assault.

Christine was mortified when the very same hospital where she worked as a sexual assault forensic nurse -- and helped craft a sexual assault response protocol -- began sending bills for her rape kit.

"Once a month, you get a reminder in the mail, 'Hey, you were raped. Hey, this happened.' It's hard to move on," she said.

Rape kits are instrumental in helping police and prosecutors convict rapists, but an investigation by CBS News found, in some states, the cost of rape kits is not completely covered by state law, leaving the victim to foot the bill.

Congress twice has rejected legislation that would have prevented victims from having to pay for their rape kits.

In Christine's case, she was billed as the result of an error. Illinois has a voucher system that pays for medical expenses not covered by insurance for up to 90 days after a sexual assault; but Christine mistakenly had been marked as self-pay, due to a simple coding error that took 10 months to correct.

She was unable to get out of bed for months after her attack. The hospital threatened to send her to collections if she didn't pay.