One of my testis is moving up and down even though i dont go through a temperature change. i notice it is triggered by my body movement sometimes it just happens randomly? also when it moves up my scrotum doesnt contract with it but remains hanging?

Testes are very mobile in the scrotum and usually move as a protective reflex by muscle in the scrotum or temp. change and body motion. This motility is sometimes variable re. each testicle. So if your testicles show no abnormality on feeling, are nearly equal in size and you have no discomfort don't worry. But if it bothers you enough have a urologist check you.