You missed the train! Whenever a child falls from a height or hits their head on something this is good reason to at least go to a clinic or the ER. Concusion can occur hours or days later, so always have your child checked over by a doctor no matter if you feel the fall wasn't all that bad and your child has stopped crying.
The fall and the fever are unlikely to be related and if the fall was a week ago and you've seen no effects it probably wasn't serious. Prolonged fever in a child of that age does however merit a visit to the doctor.