I personally would go with a pdoc's opinion first as they are a medical dr., but schizoaffective disorder is complicated. Perhaps get a second opinion from another pdoc? I would not trust a master's level clinician alone (or a psy.d/ph.d, for that matter) to diagnosis me with that.

Schizoaffective disorder Tests and diagnosis - Diseases and Conditions - Mayo Clinic

Have you had bloodwork done (as the link mentions) to rule out anything else? (My pdoc sent me to my general dr. for that before diagnosing me with MDD.) And isn't there a test for Asperger's?