I recently have several erotic oil massage in China. Each time there is a happy ending with the hand, breast or buttom of the masseuses. From the latest massage, there is almost 4 weeks. Do I have any risk of HIV and STD (e.g. syphilis)? There is no discomfort for me up to now. I am a little bit of scaring syphilis as some physicians say that a few people with the infection of syphilis may have no symptom, i.e. no chancre. Please help me and thanks a lot for your professional answering.