You are one of many people who seem to believe (or worry) that other illnesses, medications, and so on can prevent accurate HIV testing. Not true. That includes corticosteroid therapy. You can rely with absolute, unshakable certainty on your negative HIV test results.
Good luck-- HHH, MD
Even if you had gotten the virus from the single sexual encounter with a woman, a 4 month period of time passing since last taking immunity suppressing drugs I would think to provide sufficient time for HIV antibodies to develop to detectable levels. Even with the potent PEP regimens (viral suppression), I have read after 3 months from discontinuation of the drugs a test should be valid. And has often been noticed well before.
Testing at 3 months will be picking up those that are previously immunity suppressed from another disease, and always by 6 months. I think you are clean, I am sure our good Dr. will agree.
I have seen this interference with seroconversion suggested MANY TIMES, perhaps it was being presented as an extra precaution to influence extended testing. But the only 2 legitimate sources I can find do not present real evidence, and they are old. Sorry, if I have mislead anyone by stating this. Good thing we have a real doctor here to correct me.
Delayed seroconversion has been associated with simultaneous exposure to hepatitis C in two cases (Ridzon)
Ridzon R, Gallagher K, Ciesielski C, Ginsberg MB, Robertson BJ, Luo CC, DeMaria A.
Simultaneous transmission of human immunodeficiency virus and hepatitis C virus from a needle-stick injury. N Engl J Med. 1997 Mar;336(13):919-22
[PubMed ID: 97209487]
"Our data suggest that zidovudine prophylaxis does not delay the development of HIV antibodies beyond 6 months.."
Ciesielski CA, Metler RP.
Duration of time between exposure and seroconversion in healthcare workers with occupationally acquired infection with human immunodeficiency virus. Am J Med. 1997 May;102(5B):115-6
[PubMed ID: 9845512]
Perhaps a concern if you are an Asian monkey;
"The observation of this delayed infection in our model (~3 months later than in untreated controls) and recent human evidence (21) further support the need for adequate follow-up periods after PEP administration to monitor for delayed seroconversions."
Efficacy of Postexposure Prophylaxis after Intravaginal Exposure of Pig-Tailed Macaques to a Human-Derived Retrovirus (Human Immunodeficiency Virus Type 2)