Hi Thanks for posting your query on HCM I have read and understood your concern. There are many medical conditions that may cause testicles to swell.It must not always be of infectious/STI origin though it will be wise STIs are eliminated given the fact that you have a milky discharge.Some possible causes may include: -Hydrocele -Orchitis/epididymitis -Hernia -Testicular tumour though less likely in your case. I will suggest you see the Doctor for examination and some test.Tests that may help identify the cause of your problem may include: urethral swap smear, urinalysis, chlamydia, syphilis, testicular ultrasound. Your treatment will depend on test resultus. Hope this will help Wish you good health.You may write back if more concerns Best regards Dr Mbuomboh