Thanks for your question, and sorry you have been coping with so much stress about this.
You can take a look at the Know Your Chances charts to find out what kinds of infections you can get from receiving uprotected oral sex.
HIV is not passed this way (or, only passed in theory, but not in reality).
You do not need to get an HIV test if this is the only encounter you are worried about. HIV is passed through unprotected vaginal and anal sex. If having an HIV test will help you relax, you can tested 3 weeks to 3 months after this encounter, but you do not need to test for medical reasons.
It is possible to get syphilis, gonorrhea, chlamydia, herpes or HPV when receiving oral sex. You can go ahead and get tests for syphilis, gonorhea and chlamydia right now, since it has already been three weeks since the encounter. Syphilis can take up to 3 months before it shows up on a test, though, so you might want to get another syphilis test in late June. Herpes and HPV are usually diagnosed when a healthcare provider sees warts or blisters on an exam, so if you notice anything like this, go into a clinic as soon as possible.
If you are in BC, you can use our clinic finder to find an STI clinic near you.
Let us know if this helps answer your question,
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