x ray safety

Late last year I had a lung infection with mild pneumonia in one lung.  I was treated at home and recovered within a week.  About a month later I came down with a cold that turned into a chest infection not as serious as the pneumonia.  Both times I had chest x rays done the 2nd one showed I had a mild infective change.  Now 4 month later my doctor called me and said he wants me to have another chest x ray incase I have scar tissue.  I have no other symptoms and am back jogging 20kms a week.  Im not comfortable about all these x rays especially as they are on my chest and I also had 4 done for my teeth last year.  If i have scar tissue I didnt think anything could be done for it and I would rather not know as I am quiet an anxious person and would always be worrying about it.  I am 40 years old a non smoker and no health issues.