The risk of unprotected vaginal sex one time exposure for a male is very very low and the odds are in your favor regarding HIV. As for the sore throat, there are many bugs going around at this time of the year and IF the sore throat had anything to do with ARS (Acute Retroviral Syndrome, a viral infection that MAY occur in some individuals approximately 2-4 weeks after the exposure IF exposed to HIV), it would not have lasted this long. Think about how many sore throats you have probably experienced in your life. And with ARS symptoms, not everyone has them. If they do, the sore throat may or may not occur but is usually present with a high fever and rash as well. I know easier said than done, but please do not stress over this. Your risk is very minimal, miniscule for that matter because you aren't even sure if this girl even had HIV to begin with and more than likely she didn't. With that being said, for peace of mind purposes, you are 6 months past your encounter, and could take a test for peace of mind and it would be absolutely conclusive!
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