Are there stds besides gonorrhea, chlamydia, trich, hiv, syphilis, hep a/b/c that can cause intermittent pelvic pain (testes, groin, lymph, hips, lower abdomen)? all those neg at 6 wks but still have pain, no other symptoms. other potential causes?

Definitely no STD. This is not due to any infection caught from another person, either sexually or otherwise. All this sounds like genitally focused anxiety or the chronic pelvic pain syndrome (CPPS). Google it for more info; I'm betting you'll find your symptoms are typical. The wikipedia article is good; also see information on CPPS from the Stanford University Dept of Urology. Good luck.