I Am 65 Yrs Old And Have Had A Horrible

I am 65 yrs old and have had a horrible cough X1 wk. This is after a sinus infection in late Nov., The Flu in January, a stomach virus in February and now the Dr. said I have bronchitis. She did a chest x-ray on Thurs. to r/o pneumonia and I got the report from X-ray this afternoon. Naturally the Dr. is off the weekend. The impression: Mildly increased interstitial markings compatible with smoking. As mentioned, I am 65 yrs. old. I smoked occasionally for MAYBE two years when I was in my 20's. Hard to believe that's relevant. Anyway.....is this cause for concern? Thank you!