Hello. Thank you writing to us.
Oral sex carries a lower risk in terms of
HIV as compared to unprotected vaginal sex Or anal sex. Nevertheless, risk is low but not Zero.
Out of the 3 occasions when you took HIV
DUO test, the first one at 3 weeks was too early since the test is ideally don earliest at 4 weeks. At 4 weeks the test is 99.8% sensitive.
Therefore, testing negative at 6 weeks and at 9 weeks almost rules out the possibility of HIV but it is a recommendation to take up a test at 12 weeks of sexual contact to be taken as conclusive. At 12 weeks this test is 99.9% sensitive.
Most likely it would turn up as negative in your case but you must take it up at 12 weeks too for your own peace of mind.
You must also test for other STD's, specially
Syphilis by an RPR test and Pharyngeal
Gonorrhea by an oral swab test.
Syphilis can also cause systemic symptoms and swollen glands at various sites like neck, inguinal, elbow etc. Similarly, Pharyngeal gonorrhea is associated with
sore throat and swollen neck glands.
I suggest you to fix up an appointment with a specialist so as to ascertain the exact cause of these symptoms
Regards
Always practice
safe sex with a condom!!