I started having dull aching pain in my right testicle about 2 weeks ago, sometimes radiating up into my lower right groin and back, becoming so painful that I could barely walk or stand for very long at times. I went to my doctor, she ordered urine tests (twice) which came back negative for all stds and infections. She also ordered two seperate ultrasounds on my scrotum, which also revealed nothing abnormal. My question is, what then could have caused the pain I was having. Would epidymitis show up in urine tests and ultrasound? The pain seems to alleviate when I ejaculate. Really hope someone can give me some answers here.