Dear doctor.
I'm male, 28 and currently on holiday in Thailand. I slept in a hostel for a couple of nights and we clicked with one of other travelling girls. She has used quite a new (for me) excuse to get me into bed (yeah, nowadays, women, especially single ones are the hunters) saying she never had an orgasm. We had sex for the whole night - protected but with unprotected oral sex. This was the first one-night stand I have ever agreed to. In the morning we had to split up but we had a chat over coffee and she told me about her sexual past and...
I am a very prudent person when it comes to sex very often preferring to masturbate instead of using my chances as I have been brainwashed about STIs and have an experience of popping condom once in the past (that's the time when I started getting regular tests). Thing is that I live in North Korea where I cannot really get tested or, I believe, treated for STIs (even if I can, I'd be expelled out of the country if I came out positive). My next STI test, therefore, is scheduled back in the UK for August 2014. Until then, I do not want to be worried. I know the chances of having contracted something are quite slim but they're still there. My main concern is syphilis and, since my flight leaves in two days, there is no time for testing and, I am pretty sure it is still to early that they come out positive in case I got something.
So, is it a correct way to just go to a hospital and request the 2.4 MU dose of penicillin injection saying I might have contracted syphilis? Would it do much harm if no infection is present? Would it work if no chancres had a chance to pop out if the infection is present?
Thank you very much in advance.