It sounds like you have a pretty good understanding of how HIV can be passed. As you note, the chances of getting HIV from receiving oral sex are very low and there are no documented cases of HIV from having sex in this way. As for the blood, it is really hard to know if that is even a risk for you since you are not sure where it came from. Although the chances of HIV seem low, you may want to get tested to help with your worries about this contact.
You can also test for Chlamydia, gonorrhea and syphilis at the same time. These STIs can easily be passed through oral sex. Often people don’t notice any symptoms and may not know they have them. They are treated and cured with antibiotics.
Check out our clinic finder if you need help finding an STI clinic in BC.
Please leave a comment to let us know if this answers your question or if you need more information.
For other readers, please feel free to leave a comment, or let us know if this was helpful.