Safety comes first in both federal health sources. MedlinePlus says: "If you are in danger or need medical care, call 911. If you can, get away from the person who assaulted you and get to a safe place as fast as you can." It adds that the National Sexual Assault Hotline, 800-656-HOPE (4673), can "connect with a sexual assault service provider in your area who can direct you to local resources."
The Office on Women's Health, part of the U.S. Department of Health and Human Services, covers medical care in more detail on its sexual assault page. It describes calling 911 or going to the nearest hospital emergency room to be examined and treated for injuries. It notes that "the doctor or nurse may give you medicine to prevent HIV and some other sexually transmitted infections (STIs) and emergency contraception to prevent pregnancy."
The same page explains why some survivors wait to wash or change. It says that showering, bathing or washing "might wash away important evidence," and suggests not changing clothes "if possible," and not touching or changing anything at the scene. These are described as ways to keep physical evidence. They are not conditions for receiving care.
A forensic medical exam is an exam in which a trained doctor or nurse collects physical evidence, often using what is called a rape kit. The Office on Women's Health describes asking for a sexual assault forensic examiner (SAFE) or a sexual assault nurse examiner (SANE), and says the hotline can help locate a hospital with trained staff. It also states plainly: "You do not need to press charges in order to have evidence collected with a rape kit," and "You do not have to decide whether to press charges while at the hospital."
If drugs may have been involved, the page notes that date rape drugs "pass through the body quickly and may not be detectable by the time you get tested." For many survivors that is a reason to raise testing with hospital staff. The page on drug-facilitated rideshare assault explains how that question can matter later.