Diagnosed at 28 with no testing

I have recently been diagnosed with chronic bronchitis, COPD. I am 28 years old and in decent shape and live an active lifestyle, although a little over weight. I smoked for just short of 9 years and smoked “socially” for 4 of those years while in college. I was an everyday smoker for 5 years and would smoke 1/4 to 1/2 pack daily. I have been diagnosed with bronchitis twice since March and was sick one other time, however was not diagnosed with bronchitis, the most recent being middle of August and when I received the diagnoses. I established a PCP after the second time being sick. She believes that I have COPD and did diagnose me without any tests (PFT, pulse oxygen). I did have a chest X-ray to rule out pneumonia. The X-ray was interpreted by the X-ray tech as normal lung volumes however PCP is saying the X-ray was not good enough as she can’t see all of my diaphragm and believes my lungs are hyperextending. I responded well to prednisone and Levofloxacin, nebulizer treatment, and am using Advair and a rescue inhaler still. I did immediately quit smoking the day I was told this as it is very scary and has done a number on my mental health. She believes me to be early onset of COPD, but did not give me a rating on the Gold scale and did state that my damage can be repaired and then told me she would see me in a year for a check up unless I would like to get testing and a new X-ray done. My question is, can I be diagnosed with out being given a PFT test? I do have an appointment schedule at a different hospital for a second opinion. Should I insist a referral to Pulmonologist? Thoughts, opinions?