If you think you have an STI or that you have been exposed to an STI, STOP having sex immediately until you are tested and/or treated by a healthcare provider.
If you have an STI, you are at increased risk for getting HIV (Human Immunodeficiency Virus) if you are exposed to that virus. HIV is the virus that causes AIDS.
You can order a collection kit on this website to be tested for chlamydia, gonorrhea, and trichomonas.
There are many more resources to learn about STIs and STI-related issues. There are also ways you can anonymously notify your partner of their need to get tested.