The fall on outstrected hand is a very common incident for each of us. It is because of the reflex defense confirmation of our body during a fall to extend the limbs first to save the axial body structures like the head and other central body parts. Anyway, the wrist is an area which is very crowded with bones consisting of d carpal bones, the distal radius and ulnar head. So sometimes there may be a subtle  injury or fracture to any of these bones and d joints between them which is not manifested immediately after d injury because of lack of displacemnt of d fracture segment due to crowding of d area . Eventually with activities like weight bearing the fractured bone or injured joint gets loosened up and symptoms like you hv mentioned starts to manifest.