What could be causing my epidymitis?

[Duts9]

I recently saw my GP about a dull ache and a swollen  right testicle. I had also been tested for STDs which came back clear. My doctor prescribed 14 days of doxcycline (1 100mg capsule per day). The swelling and pain seemed to clear after about 7 days. However I am now on day 12 of antibiotics and I still have pain in my right testicle. What could this be?
I am also starting a new relationship and unsure if it is safe to have sex despite being cleared of STDs. This issue is really stressing me out

[CHIN_C]

In males 14-35 years of age, epididymitis is most commonly caused by STDs such as Neisseria gonorrhoeae and Chlamydia trachomatis. In males of other ages, epididymitis is most commonly caused by UTIs such as Escherichia coli. Less common causes include other infections such as mumps or TB, trauma, or drugs such as amiodarone hydrochloride.

[auntiejessi]

What kind of testing did they do for you? Urine? Urethral swab? What did they test you for?

There are other causes, too - an injury, a blockage, an enlarged prostate - https://my.clevelandclinic.org/health/diseases/17697-epididymitis

Have they done any imaging?

[Duts9]

They did a urine test and also a blood test for HIV and syphillis. All tests came back negative.
My GP said that even if tests came back positive the doxcycline would clear the infection.
I have been off the antibiotics for 1 day, the testicle is still tender, my penis stings a bit with thrush like symptoms too.

[GuitarRox]

Hey.  Question.  If you came back clear for STD's, don't you mean you were negative?  So, your question about safe sex and being cleared for std's is confusing.  Don't you mean they eliminated std's as the reason for the issue?  So, you won't give a new partner an std if you are negative for any and I wouldn't worry about that.

The antibiotics have cleared everything up by pain in right testicle?  When you finish the 14 days, if that is still going on, I would let your doctor know if it continues.  You may need a different or second round of antibiotics.  I'd do another round of testing to see if the bacteria is cleared. E Coli also causes it and there are other bacteria as well.  Use good hygiene.  I'm sure you do but be proactive to make sure from now on. Here is an older post from guys who have had this and several were on antibiotics for a full month before it fully resolved.  https://www.medhelp.org/posts/Urology/How-Long-Does-Epididymitis-Take-To-Go-Away/show/1141246

[Duts9]

Hi, sorry the std results were negative. The doctor also said even if they had have been positive the doxcycline would get rid of them.
The 14 days are now up, the swelling has gone down but still my right testicle is tender. I also have slight pain just over my groin. I also have thrush like symptoms which I have had on and off for a while and the canesten cream doesn't seem to be helping. Could this be a cause of the epidymititis?
I've booked to see my GP again in a few days but the stress of all of this is driving me mad