Welcome to the forum.
You had a low risk exposure. Oral sex is inherently low risk for all STDs and zero risk for some. Your HIV test results prove for sure that's not an issue. You don't say exactly what STD tests were done, but the negative results are reliable. However, if testing didn't include a throat swab for gonorrhea, that might be something to discuss with your doctor. (The normal "STD panel" only includes urine testing for gonorrhea and chlamydia, which of course cannot detect an infection at a different anatomic site.)
Still, oral gonorrhea rarely causes symptoms at all and is not a likely cause of ongoing sore throat. Chlamydia rarely infects the throat at all and also causes no symptoms, so that's also not a serious consideration.
Self-perception of enlarged or inflamed lymph nodes is often (usually?) erroneous. If your doctor agrees your neck nodes are enlarged, they probably are -- but if not, I would disregard that symptom. Also, looking at your comment below, throat discomfort or "tiredness" certainly doesn't suggest pharyngitis.
So I can't tell you what is causing your throat symptoms, except that I'm confident they are not due to any STD. Perhaps it's just physical manifestations of anxiety over a sexual decision you regret -- but it isn't an infection from that event.
For reassurance, have a gonorrhea throat swab if not yet done, but I don't expect it to show anything. Beyond that, I recommend no further STD testing.
Best wishes-- HHH, MD
I should add that the pharyngitis has not really cause any pain. I feel like my throat (or i guess my pharynx) gets "tired" easily...
*I cant really say that the pharyngitis doesnt cause me any pain, but i do find that at random times i get quick pain behind my left inflamed pharynx but very minimal..
Im sorry Dr., I forgot to mention that the day I found out I had viral pharyngitis , they did a throat swab to see if it was caused by bacteria. Even though the Dr. was sure it was caused virally he still gave me a prescription for penicillin which he advised me not to take until i found the results for the throat infection. Being a hypochondriac that I am, I still took penicillin for 3 to 4 days before find outing out the results.
I know I am a worrier and can understand that some of my symptoms are of me just being worried, but why would I have such inflamed pharyngitis and for this long. its been almost 2 months that my throat has been so inflamed, it looks horrible.
In my opinion, two mistakes were made: the doc should not have prescribed penicillin at all, since 90% of pharyngitis is viral; and you should have followed his or her advice and not taken it.
I doubt you still have "inflamed pharyngitis"; self examination is very unreliable, and I'm pretty sure that even if the problem started that way, the pharyngitis per se is now gone and you are left with symptoms that do not indicate current active inflammation. If in doubt, though, consider seeing an otolaryngolotist (ENT specialist) for a second opinion.
In any case, still no STD concerns. So that will end this thread, since STDs are the only topic here. Do your best to move on without worry. Best wishes.