A rib fracture is one of those things that can happen from the most simple fall or knock. They are inordinately painful and disabling given that you still need to move the rib to breathe.
In the first stages it is strapping up if very painful, but really you just have to work your way through it. Please be sure you have no other symptoms in the lungs that can occur if there is a displaced fracture.
It is once the fracture has healed that it is important to restore normal function to the ribs, breathing pattern and thoracic spine movement. This is at around 6 weeks.
It is easy to stiffen up and allow the dysfunction to set in. This leads to further problems down the line. Get it seen!