Hi, I Have A Positive Mantoux Test In Year 2014

Hi, I have a positive mantoux test in year 2014 and so since then, my doctor requires me to have my annual chest x-ray. For the pst 2 years (2014 and 2015), my X-ray results are always clear. This year (2016), my chest x-ray shows scarring of Right middle lobe. What could this be? Is it a dormant TB or an active? I don't have any symptoms showing that I have TB. I never recall too having cough, flu or any disease this year aside from sore throat. My doctor is suggesting 2 options: 1. to see a respiratory doctor, 2. is to have a repeat of chest x-ray. What is the best thing to do?