1. Go to a safe place.
2. If you want to report the crime, notify the police immediately on 911 (767 or 112 if in Lagos, Nigeria). Reporting the crime can help you regain a sense of personal power and control.
3. Call a friend, a family member, or someone else you trust who can be with you and give you support.
4. Preserve all physical evidence of the assault. Do not shower, bathe, douche, eat, drink, wash your hands, or brush your teeth until after you have had a medical examination. Save all of the clothing you were wearing at the time of the assault. Place each item of clothing in a separate paper bag. Do not use plastic bags. Do not clean or disturb anything in the area where the assault occurred.
5. Get medical care as soon as possible. Go to a hospital emergency department or a specialized forensic clinic that provides treatment for sexual assault victims. Even if you think that you do not have any physical injuries, you should still have a medical examination and discuss with a health care provider the risk of exposure to sexually transmitted infections and the possibility of pregnancy resulting from the sexual assault. Having a medical exam is also a way for you to preserve physical evidence of a sexual assault.
6. If you suspect that you may have been given a "rape drug," ask the hospital or clinic where you receive medical care to take a urine sample. Drugs, such as Rohypnol and GHB, are more likely to be detected in urine than in blood.
7. Write down as much as you can remember about the circumstances of the assault, including a description of the assailant.
8. Get information whenever you have questions or concerns. After a sexual assault, you have a lot of choices and decisions to make - e.g., about getting medical care, making a police report, and telling other people. You may have concerns about the impact of the assault and the reactions of friends and family members. You can get information by calling a rape crisis center, a hotline, or other victim assistance agencies.
9. Talk with a counselor who is trained to assist rape victims. Counseling can help you learn how to cope with the emotional and physical impacts of the assault. You can find a counselor by contacting a local rape crisis center, a hotline, a counseling service, other victim assistance agencies.
Source- 911 Rape.org