Sir, when i go to swimming i found that my penis left ball is taking up towards my stomach & my ball bag is too smaller, is it any illness?

Not an illness. : The cremasteric muscle pulls your testicle up closer to your body as a normal response to expsoure to cold. This is a normal reflex but if too strong, the testicle can get lodged into the inguinal canal area and may need to be manually reduced back down into your scrotum.

No : This is normal. The testicles move around to maintain their temperature. When the outside is cold they retract and when warm they drop.