Why does my tibia hurt in the morning and after i get up the pain starts to go away?

Check it out: B"sd not sure - stress fracture would hurt more when you walk as would tendon insertion inflamation (enthesopathy). Physicain may want to assess for bone cyst, tumor or Pagets disease - probably with imaging - eg Xray, CT/MRI, bone scan and maybe some blood tests - eg alkaline phosphatase, bone breakdown marker.

Unusual: That is unusual, I would not hesitate to be seen. Could possibly be a pinched nerve in the back. Most conditions in the tibia itself that would cause pain would be worse during the day when you are up on it, so I do think it would be good to have it looked into.