Thank you for your query,
There are many causes of lung infection
like viral, bacterial and tuberculosis
And the treatment for each cause will vary according to its causative organism.
The injection test for TB is called mantoux test
and it is done to rule out TB if the doctor suspects depending on clinical profile or wants to rule out by looking for the result of the test.
Nothing to worry, wait for the reports of chest x ray
and mantoux test result and the doctor will advise you the proper management.
Hope I have answered your query.