Buttpain, left testicle pain, leg pain.

I had sex only once in my lifetime and that too two years ago with protection though I had done oral sex and fingering to her vagina.since I haven't been in active sex.but for six months i have sudden urge to urinate after drinking some water regularly as that wasn't case previously and thrice whitish discharge with no pain.since last few days I got some pain in my left testicle and left leg,thigh, mad groin so I went for a STD test which was all negative except Chlamydia IGA positive and igg,igm negative.but doctor said by physically checking my testicles that I don't have Chlamydia and prescribed me 20 tablets of norflox 400 for 7 days.after that I still feel pain and burning sensation and little numbness  in pelvic area and pain in my left testicle,buttock and left leg now I am prescribed co-trimoxazole for 10 days but still problem persists.....suggest something.. can it be prostatis?