The risk of an HIV infection during oral sex is unlikely. Even if someone cums in your mouth, the probability is very low.
Small injuries in the mucous membrane due to deep throating or the use of drugs through the nose raise the possibilities of potential infection.
Other sexual transmitted infections (STI’s) such as chlamydia, gonorrhea and hepatitis A and B can however be transferred while giving and receiving oral sex. In that case you can get treatment at the nearest clinic or at the doctors office.
Keep in mind, that some infections can be symptom free.
Get tested several times a year for HIV, hepatitis C and other sexually transmitted infections (STIs). Swabs for your throat, dick and ass are the best way to find anything that doesn’t belong there! Vaccinations against hepatitis A and B are available.