I had unprotected sex with an unknown woman hardly for a minute about a month back. After about four days, I got cold and a kind of sore throat, but not exactly sore throat. I got tested for HIV (Human Immunodeficiency Virus) after 15 days and it came back negative. Now, for the past one week, I have a feeling of something stuck in the throat and a constant need to clear the throat. But, I have not experienced any pain or difficulty in swallowing. I am extremely stressed, anxious and in fear of HIV. I am not able to do anything or concentrate on anything for the past one month. In spite of all this, I have been travelling a lot for the past one month. The only thing I can rely on is that after the act she asked me whether I was clean. Please help.