Superficial blood clot). when i go swimming do i have to wear compression stockings in the pool? if not needed how long the period without?

You don't need to: Superficial clots or thrombophlebitis, meaning those not involving the deep venous system do not require compression stockings.

First ask doctor: If your doctor has approved swimming, the water pressure is good for your circulation. Usually stockings aren't needed under water, but need to be applied immediately after. I have had patients swim in compression stockings and then just shower off the chlorine, because of the difficulty applying.