I had oral sex with a prostitute. she had my penis in her mouth for about 20 seconds before I put a condom on. 4 days later, I had a 101 degree fever, chills and very tired. I went to the doctor but did not mention the encounter. He gave me antibiotics and now I feel fine. Could this have been an std ? Is it ok to have unprotected sex with my girlfriend now ? Thanks for your help.