Can I be fired while my medical leave/disability claim extension is being appealed.

I had a surgery and have been out on disability and medical leave(not FMLA). I asked for an extension and submitted my physical therapy notes. I recieved a voice mail saying the notes do not sure a physical impairment even though the notes clearly state a 25% physical impairment. In the past I would submit doctors notes requesting additional time off and i would be told that shows no physical impairment and that i could submit physical therapy notes and those would be accepted. This time I only submitted the physical therapy notes. I would like to know if my company will allow me the time to appeal the denial or if I may be terminated immediately upon return due to administrative counseling based on not meeting their attendance requirements. I would like to appeal the medical leave decision and if worse comes to worse I would like to have the opportunity to put in my 2 week notice so I have a clean job history.