Hello, Welcome, I understand your problem. It is most likely due to epididymitis which is inflammation of epididymis (a small structure just above the testes). It can also be due to a very similar looking condition know as torsion of testes. But in that situation, pain is severe, arise quickly and will be felt on entire testis and it will feel more fixed as compared to normal mobile testis. Epididymitis usually occurs due to bacterial infection. So, antibiotics like cefixime, azithromycine or doxycycline needs to be taken along with anti inflammatory like ibuprofen. I suggest you should consult a GP and get the treatment. Hope this will be helpful. Thanks for your question. Take care.