Talk to Pulmonologist / Lung on Asthma/Lungs

Dear Doctors, I am 27 years old. I was born premature and had the issue of asthma by birth. In my childhood, I used to take ventolin syrup and ginger n honey(for my chest) till the age of 12. After the age of 12, I was fine until the age of 21 and faced the issue for a week. In 2014, I moved to Pakistan From Saudi Arabia for my studies and I started feeling the problem of asthma in 2016 during the work days of BRT, Peshawar and I realized that it is due to dust. I used to cover my nose and mouth with a mask while going to university and Donot feel the problem when I cover my nose and mount. Dr. suggested me to take combiviair when ever I feel the issue. last year in march 2020, I used to feel the same problem without being exposed to dust. now a days i am also taking combiviair 200mcg at night. One thing I noticed that I am having a knee pain also and someone told me to have a proper test for lungs in order to know the problem. Kindly suggest me what I should do.