Good morning -  I hope you are well. 3 days ago I engaged in unprotected oral sex with a man. I performed brief fellatio on him and then he did the same to me. Neither of us ejaculated in the other’s mouth. Time with penis in mouth less than 20 seconds. I understand my risk is low, but is 3 days long enough for urine test for chlamydia and gonorrhea? Do I need a throat culture? 

Welcome to our Forum.  Thanks for your questions.  Your risk of infection is low.  Three days following your encounter a throat swab tested using any standard NAAT test would detect gonorrhea or chlamydia if present.  A throat culture is not needed and would be less sensitive than a NAAT test.  If you are going to get tested, since you also received oral sex, to thorough I’d get a urine test for gonorrhea and chlamydia as well.---

understood. would 3 days post exposure be sufficient for accurate urine test as well. Again, I believe my risk is extremely low, but I feel compelled to test. 

As I said earlier, testing at three days will provide a reliable answer.  This is true for infection at any site.  EWH---

Thank you. I suppose it doesn't matter that the exposure was at 3pm on Tuesday and the test was 10am on Friday not "quite" 3 days, but that seems like splitting hairs. I appreciate your time and will consider this discussion closed

Correct. I’m glad I could help.  EWH---