You do not have HIV. For starters, the exposure you describe was zero risk for HIV, hepatitis of all sorts and other STDs. Thus you never needed testing and you have taken your test results at 8 weeks, 11.5 weeks and at90 days as proof that you do not have HIV. Finally, let me tell you with confidence that the idea of "late seroconversion" is essentially an urban myth.
Folic acid is largely taken in from the diet. You should work with your doctor to sort out the origin of your laboratory abnormalities. You do not have HIV.
I hope this comment is helpful to you. EWH
Just one last question. Could autoimmune diseases such as Common variable immunodeficiency CVID cause late seroconversion or delayed seroconversion.Or even malasorption diseases.I have been losing a bit of weight of late.