pain in pelvis & testicles(sometimes) help!!!

Hi, I am a 24yr old male. I had an unprotected sexual encounter 2 years ago. We used bath/body soap for lube after the condom came off. Shortly after, my pe**s and testicles were hurting for a while, up until about 5 months after, but have subsided and they don't hurt anymore (testicles hurt sometimes, but RARELY). I had chlamydia and gonorrhea tests done which came back negative, and the doctor said my urine looks perfect.

I didn't have any pain anywhere for a while, then about 8 months or so ago I have been having pain in my pelvis area. (sometimes testicular pain). It's basically on both sides of the pelvis, below my waistline (to the right and left of my privates)...the pain is OFF and ON and doesn't hurt too bad when it comes. Doesn't hurt to push on it. It might not be there for a week, then the pain might come for about 10 seconds then go away.

I went to the doc recently, and he checked me for a hernia and basic stuff, said I was fine. But he suggested getting an ULTRASOUND done on my abdomen or pelvis i think he said. To see if there are any strains, damage, kidney stones, etc.

What does it mean when my symptoms are OFF and ON, like they come and go?
Could this be a sign of cancer? or STD related or something? :(
Does this sound serious? Deeply worried...

Thank You -

[scrutinizer666]

i wish i could give you an accurate answer!
could be allot...
did you get your prostate checked?
does it burn when you urinate?
did you have abdomen pain,or  somewhat of a burn around any of your lymph nodes?
just start checking things, pay attention to yourself,& try to stay on the safe-side (safe-sex,clean... approved lubes... you get the picture)
hope things turn out well!
good day.

[FellowAmericans]

-yes he checked my prostate and said it looked fine...
-does NOT burn when i urinate
-is your abdomen higher up from your pelvis? I have pelvis pain (don't know where lymph nodes are)