Doc, I made a big error in judgement and ended up with a prostitute last night. She performed unprotected oral sex for about a minute and then we had sex using a condom. We washed ourselves before and after our activities. I have read that the risk of contracting an STD is low and that I should get tested, but is there anything that can be gained medically by taking a z-pack to try and prevent an STD from taking hold in my system? I expect you will tell me to wait to see a doctor first, but can the z-pack be used to keep an STD from developing before symptoms are noticed?