1) Would you recommend testing in these scenarios?

I had some symptoms 3 days after the events described, namely a runny nose and sneezing, which then became a headache, feeling like having a cold and some joint pain and a couple of days with diarrhea. The symptoms don't fit the timeline nor suggest HIV.

I tested negative with AB only test at 16 days post exposure
I tested negative at 18 days post exposure with 4th gen AB/AG test

I tested negative at 23 days post exposure with 4th gen AB/AG test
At day 28, I went in for another 4th Gen test and got a call from lab saying it was indeterminate, So that same day I had to come back to the lab and get another 4th gen test as well as an AB test which came both back negative (for reference 4th gen combo test was 0.41 negative). The lab technician said the first test was faulty, per human error, and assured me to dismiss it.

Day 30 I had another test AB only which also came back negative.

I recognize i am severely over tested and, I believe the tests rule out that symptoms are due to HIV infection. 

2) Thoughts?

Testing has both clinical and personal/psychological benefits. From a clinical/medical perspective, I would say there was no need for HIV testing following either of these two exposures. Both were extremely low risk, both because it is very unlikely the first partner has HIV, and HIV is never sexually transmissible when an HIV infected person is on effective treatment with undetecable viral load. For someone having ongoing sexual exposures like these, I would advise periodic testing (e.g. every 6-12 months) and not after each event. However, from the personal/psychological perspective -- the ability to stop worrying, reduced stress, sleeping well, etc -- a negative test result often is very beneficial even if the actual risk was very low. On that basis, I have no problem with your decision to be tested again for HIV.

Acute retroviral syndrome (ARS, i.e. initial HIV infection) generally does not nasal congestion, sneezing, etc. And three days is much too soon for onset of ARS symptoms. You caught a cold -- which could have been from one of those men, or from anyone else in your environment.

As for your test results, I'm glad you already understand you were overtested -- as just implied by my comments above. The negative results prove for sure that any symptoms you have (or had) were not due to ARS. However, the AgAb (4th generation) HIV blood tests are not 100% proof agaisnt a new HIV infection until 6 weeks after the last exposure. All in all, the chance you have HIV is zero for all practical purposes. But if you need the additional reassurance to reach truly absolute certainty, have one more test in another two weeks. 

Those comments address both your questions. I hope they are helpful. Let me know if anything isn't clear.

HHH, MD

2) In the hypothetical scenario that the first person I gave oral to was positive what would the assessment over this risk be?

3) For AB only test when can I test conclusive given these exposures? Its day 33.

4) If the symptoms were due to HIV, both tests: either AB/AG or AB only surely would've been positive by now? 

2) If the first partner had HIV, your the risk you have HIV would still be under one chance in many million.

3) The standalone antibody tests are conclusive after 8 weeks, although some conservative resources might still advise 3 months.

4) This was answered above:  "The negative results prove for sure that any symptoms you have (or had) were not due to ARS." The symptoms of HIV are not caused by the virus, but by the immune response to it, which is measured by the antibody tests for the immune response. It is never possible to have HIV symptoms without a positive Ab test.

3) do you recommend wearing condoms for oral sex for all STIs?

Thank you very much! Im free from this worry, as I read a lot of info in this forum.

2) Yes, conclusive.

3) Most experts consider condoms optional for HIV prevention during oral sex. However, they protect against other STDs more commonly transmitted by oral sex, like gonorrhea, NGU, syphilis, and herpes due to HSV1.

Thanks for thanks. I'm glad to have helped. Best wishes and stay safe.