Pain in wrist when coughing following injury. initial diagnoses capitate fracture but was ruled out today and was informed of no fracture (misdiagnose?

Hard to say: It is really hard to say without the benefit if an exam and review of your X-rays. It is not terribly uncommon for initial X-rays to suggest a fracture and then have subsequent X-rays be normal. If the pain is persistent and severe, a ct scan or MRI are much more sensative tests for injury than an X-ray. Don't hesitate to seek follow up and/or a second opinion.