thanks for reaching out, I can tell you feel worried and that's a tough place to be in. The risk of transmission of course depends on if the person is living with HIV but I should mention that when a person takes treatment and their viral load is undetectable, the rate of transmission is essentially zero. I thought you might find this article helpful on the topic, https://h-i-v.net/living/undetectable-untransmittable.
The risk of transmission also varies based on the type of intercourse. The five fluids HIV can be transmitted through are breast milk, blood, precum, semen, and vaginal secretions (not saliva.) In the case of transmission through oral sex, the risk is at the lower end of the spectrum compared to unprotected vaginal or anal sex. You can definitely learn more about the specifics which may ease your mind through this article: https://h-i-v.net/transmission.
If you are interested in getting tested, I can provide some information on that, too. Just let us know. I wish you the best - Liz (Team Member)