I think that it is unlikely that these tests missed a HIV infection. We find that the 4th generation antibody/antigen HIV test would pick up most HIV infections by 6 weeks and give you a final result by 3 months. It seems like you had testing done after 3 months which would indicate that HIV was not passed to you.
It can certainly get really scary when you have a high risk encounter and then you get HIV seroconversion symptoms. It is common for us to see this in the clinic were this happens and the HIV test is negative. It is a good reminder for us that the HIV seroconversion symptoms are just general symptoms that can be caused by many different conditions.
As you are still having the symptoms I would recommend seeing a health care professional for further investigation to the cause. It can sometimes take a bit of time to work out what is causing the problem but at least you know it is not HIV causing the problem. If someone was getting symptoms related to HIV the viral load would be very high and a HIV NAAT test would also pick that up.
Let us know if this does not answer your question or if you have any more questions or concerns.