Welcome to the forum. Thanks for your question, and for reading other threads on the forum for questions similar to your own.
I disagree with the opening of the response you received on the community forum, "HIV transmission is not a game of numbers and statistics." In fact, that is exactly what it is, and I congratulate you on the analytical approach you have taken to assessing your risk.
Of course I don't congratulate you on your decision to have sex with a new partner without using a condom. Still, as you correctly calculated, the chance you caught HIV is extremely low. It is true that HIV is far more common in black Americans than in other racial or ethnic groups (and not because of greater "promiscuity" in African Americans); this is discussed in detail in the threads linked below.
http://www.medhelp.org/posts/show/1261996
http://www.medhelp.org/posts/show/717093
However, it is still very unlikely that the rate of 1 in 60 of all AAs in your state having HIV applies to a 22 yo female college student, and the odds are strong you were not exposed. And as you already have seen elsewhere, even if she had HIV, the transmission risk for a single episode of unprotected vaginal sex, female to male, averages around once for every 2,000 encounters. Your symptoms don't concern me at all; they are not typical for HIV, and there are some common-sense, alternative explanation, of which you mention two (allergy, anxiety).
For peace of mind, I recommend you be HIV tested -- not because the risk is high, but because a negative test probably will be more reassuring than all the scientific rationale and statistical analysis I can provide. If you find a clinic or physician where the HIV duo test (for both antibody and p24 antigen) is offered, you can have a definitive test any time 4 weeks or more after the exposure; or 6-8 weeks for a standalone antibody test. (As discussed many times on this forum, it is rarely necessary to wait for the officially recommended 3 month mark for a reliable antibody test result.)
In the meantime, why not contact your partner and tell her your concerns? You may find she is just as worried as you are -- after all, in general women are more at risk for HIV from their male partners than the other way around. You both probably would be reassured to know the other is HIV negative -- and neither of you would have to go through a few weeks of uncertainty.
I hope this has been helfpul. Best wishes-- HHH, MD