I have slight pain in my left testicle with slight swelling, i am worried that it is a torsion. is it?

Testalgia: Torsion of the testis is indeed an emergency. If you really feel that this is a possibility, get examined at once in an er. I might add that "slight" pain and "slight swelling" are usually not indicative of torsion. More often this is frome epididymtis, which should also be evaluated by a physician but is usually traeated with antibiotics.