Why do i get a dull ache in my right testicle every now and then subsides?

Have you ever had epididymitis or trauma in that testicle? If so occasional discomfort may occur. However, I recommend consulting a physician or urologist for a testicular examination. An ultrasound may be ordered as part of the evaluation

If there is no swelling or bump or lump wear a good support umderwear. if no better in a week or two pl see a Urologist