Ron, I do not believe there is any specific correlation between your left kidney stone treatment and achy pain in the right testicle. Blood in the semen usually comes from the prostate gland. It is generally due to a tear in one of the fragile veins of the prostate gland or an inflammation of the prostate(prostatitis). Bleeding may occur during sexual excitation, ejaculation, from straining with bowel movements, or during urination. The prostate is the organ that produces the majority of the seminal fluid in response to sexual stimulation. When the prostate contracts at the time of ejaculation, a vein may tear and blood mixes with the semen(hematospermia). Red blood indicates new and dark(brownish) discoloration indicates previous bleeding. In addition, prostatic bleeding frequently is associated with gross blood during urination. This typically will occur with initiation or at the end of urination(as opposed to being throughout the entire stream). With the latter, it is often manifest as spots of blood on the underwear, pajamas or bed sheets. Irritation of the gland(prostatitis) can also cause it to become inflamed and predisposed to bleed. An inflamed or congested prostate gland, especially one with varices, can start bleeding if ones strains during a bowel movement. This occurs because hard stool can actually push on the adjacent gland precipitating bleeding or straining in itself may cause the varices to rupture.
Some factors leading to inflammation include too frequent or too infrequent ejaculation, sexual arousal without ejaculation, withdraw at the time of ejaculation, excessive alcohol or spicy foods, prolonged sitting or bike riding, etc. The prostate may then become secondarily infected and require antibiotic therapy for cure. Symptoms that might occur with prostatitis include frequency of urination, slowing of the urinary stream, burning with voiding or ejaculation, burning in the penile tip unrelated to voiding, urethral discharge, sexual dysfunction(such as difficulty with erection), aching in the penis, testicles, and discomfort in the lower abdomen, low back, groin, rectum or perineum(the area between the scrotum and rectum – between the “wind and the rain”) and constipation. Most likely your testicle ache(assuming your testicle is anatomically normal) is referred pain from the prostate gland.
Sometimes as the prostate gradually enlarges with age, friable veins called varices develop on its surface. These are also prone to tearing. In such cases, Proscar or Avodart is sometimes prescribed to shrink both the prostate and the veins. Although hematospermia is not a typical sign of prostate cancer, its presence may indicate an increased risk of prostate cancer.
I suggest that you arrange for a consultation with a urologist to evaluate & treat your problem. Good luck.