The causes of a headache and nausea include many different problems and conditions, and I recommend that you schedule an appointment with your primary care physician
. First, are either you or her at risk for HIV (has she had many partners or used IV drugs)? Has she already been tested? If she does have HIV then statistically the chances of HIV transmission from female to male in one act of unprotected vaginal sex is on the order of 1 in 800. Acute HIV which is the illness that occurs when people first get HIV is a condition that resembles the flu and includes symptoms of fever, sore throat
, swollen lymph nodes, and fatigue.
I would suggest that you schedule an appointment with your primary care physician. If you are concerned about STD transmission, then you should consider getting tested for the more common ones such as chlamydia or gonorrhea. If you have no symptoms, then your doctor
may not test you. Your doctor can also perform HIV testing as this is something that should be done in everyone at least once in there life.