Hello Dr, thanks a lot previously for answering the questions online. My issue is: three months ago I had unprotected sex with a stranger, I was in a party and drank a lot. I can hardly remember anything except waking up in a stranger's bed. I was very worried and waited the right time to do the STD tests. A month later I started having an itch around my anus (I didn't have anal sex) and then it started in the urethra, suddenly started coming out a discharge. I went to the doctor and he sent me to do urethral swab tests, all came up negative except for ureaplasma and I was given antibiotics. A month later I discover three little lesions in the foreskin that became a big one within a couple of days, a went back to the urologist and he told me that it was a yeast infection, he gave me another antibiotic and sent me to the lab again, I did all the blood tests but all came negative but the lesion didn't go away and was itchy, painful and had swollen. I went to a dermatologist and after examining the lesion she was sure it has to do with syphillis. She said that because of the antibiotics taken before that's why it came negative the results of treponema. I had two benzylpenicillin injections (1.200000 U.I each) and she advised me to redo the test within a month and it doesn't matter if they come negative I should get other two shots of the same penicillin again after the test. Is it that correct to get twice of the treatment within a month? because I've read that this type of penicillin is dangerous and remains for many years in the body, and also is it normal those injections are very painful? Thanks a lot and I really appreciate your patience and time.