What is wrong with me , do i have a STD? I have a few bumps, not in one place?

I had about a year ago in august, came up with a blister got tested about a month later, everything came back negative. Now last month in April i came up with a few pimple like bumps and irritation in the and testicles. the bumps are small and about 3 or 4 in random places on my dont hurt or itch. My and testicles have a slight ache that happens once in a blue moon every other day for about 3 week now. I t doesnt hurt when i pee, its kind of relieving. I tested again last month and everything came back negative again, but i still get annoying irritations. Also after , aboutseveral hours later i get a bit more irritated than usual, only after . I also get slight pains in my legs and , but i dont know if thats cause of working or Tae Kwon Do in which i do every day. Can someone give logical explanation of what could be wrong with me?