Suggest Remedy For Unprotected Sex

Hi, I'm leaving in India,chennai. My sister is 25 yrs and she has a boyfrnd. She says that some 20 days back her boyfrnd and she had foreplay and now she is afride if her boyfriend had unknowingly done some thing. She is very much upset and i got this out of her mouth after long conversation. I want to have this confident and request to guide me as to whom i can approach.