How do u know if you broke your wrist n how long do u need to keep a cast on it?

i was running in the woods and i triped over a tree branch idk remember how i feel or anythin but i can some what move my finhgers but its hurts very much even when im not movin but i have a some what of a sling on it so by that do u think that a broke it n if so how long do i have to keep the cast on it can i go in the ocean or swimmin thnks