Hello, There are several possible reasons for a burning sensation after multiple cases of unprotected sex. As you mentioned Chlamydia is a possibility. You have taken treatment for Chlamydia - I presume Azithromycin. This would in most cases alleviate symptoms in the coming days, however antibiotic resistance in Chlamydia is rising, and patients can no longer be completely sure that the standard treatment will work. Gonorrhea is another possibility, however gonorrhea is not as prevalent (seen as often) as chlamydia. Gonorrhea has, in the last few decades, proven increasingly more difficult to treat due to resistance patterns. Both Chlamydia and Gonorrhea can cause pain in testicles (epididymitis) and discharge + pain when urinating. A 3rd possibility is infection by the STD mycoplasma genitalium , which is rarely talked about but nonetheless also a factor in current STDS. Lastly, there is the possibility of you contracting an urinary tract infection - this can also lead to the symptoms you are describing. To summarize, there are many different possibilities for the symptoms you are describing. I would highly suggest visiting a doctor to get tested properly, so that you do may treat an infection before it causes any damage. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Maria Riechel-Sarup, General & Family Physician