Many thanks up front for your advice.

Two weeks ago I visited a female CSW. She performed protected oral (fellatio) on me. I performed unprotected cunnilingus on her. We also had protected insertive sex. 

Three days later I experienced lower back pain. It mostly went away after a few days, but occasionally has a sharp pain. I  also started having eye twitching and watering in my left eye. Other symptoms are slight aches in my testicles and lower abdomen. No rashes or sores. No penile discharge.

Should I be concerned enough to get tested? I’m inclined to move in and assume the symptoms are mostly due to anxiety. I don’t want to put my regular partner at risk. This seems to be a low risk event based on reading your answers to similar situations. 

Thanks for reading other threads with questions similar to your own. You have correctly predicted my response. You describe an essentially risk free exposure. Oral sex is low risk in general, even with condom protection; that part of your exposure can be dismissed entirely. And condom protected vaginal se is nearly 100% protection against those STDs transmitted primarily through genital fluids (like gonorrhea, chlamydia and HIV) and less complete but still good protection against those transmitted skin to skin (like herpes, HPV and syphilis). Cunnilingus is especially low risk, even unprotected.

As for your symptoms, they don't fit with any STD. They are quite nonspecific, i.e. not pointing to any particular cause, but certainly are consistent with anxiety magnifying minor symptoms or even normal body sensations that otherwise wouldn't be bothersome and often not even noticed. I'll also add that whenever someone suspects his or her own symptoms have an emotional or psychological origin, usually s/he is right!

Do you need testing? From a risk or medical standpoint, no. And if somehow I were in your situation, I wouldn't be tested and I would continue unprotected sex with my wife without the slightest worry of infecting her with anything caught during these events. That said, sometime even when risk is nil, people are more reassured by negative test results than by professional opinion, no matter how expert. (We don't take it personally!) If that's how you feel, you could have urine testing for gonorrhea and chlamydia, a throat swab for gonorrhea, and blood tests for HIV and syphilis in a few weeks. However, I really don't think it's necessary.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Just a general question for future understanding: When symptoms are actually due to STD infection, I assume they would be more obvious, not be intermittent, and would get worse without treatment?

I.e. syphilis symptoms would have an obvious sore, gonorrhea would have noticeable discharge and a lot of discomfort, etc…

Thanks again for your advice and support!

The symptoms you describe don't fit with any STDs. No matter how mild or severe they might be, they're just the wrong symptoms.