I have a semi-soft, marble sized lump in my sack that gives me mild pain. It's not on the testicle itself, rather lower than the left one. I went to the doctor a year ago and he told me it was nothing; that sometimes the veins get tangled up down there. But it still gives me pain, not all the time, but about once or twice a week. Should I go to a second doctor to get re-examined for a second opinion?