Hypothetically if a woman gets raped by a close friend she knew for over 2 years how?

Would she go about finding out if she is pregnant or not? And if the guy is a foreigner does he have diplomatic immunity if he raped the girl in america but lives in russia? And lets say she found used condoms on the floor and woke up in his room the next morning. How can she prove or find out if it was a "date rape drug?"