Do I have lung cancer. I'm a smoker and my cough is really worse this month?

About 14% of. Smokers get lung cancer, but cough may be chronic bornchitis or emphysema. Other continued smokers get head and neck, bladder, pancreas cancers, heart disease and and COPD sufficinetly bad to account for death in 50%. You can still stop. This is at least a warning.
Not too late to stop. Cough is a very common symptom in smokers.Especially if you are a chronic smoker, the chance that you have a chronic lung disease-like emphysema, bronchitis etc-is very high. As you know, the more cigarettes and the longer you've smoked it- the higher your risk for lung cancer. Your cough could be related to your bronchitis/emphysema vs infection vs lung cancer etc. Quit smoking and see your md!
Stop smoking! The national lung screening trial has demonstrated that people who are aged 55-74, heavy smokers, or quit within 15 years have increased survival if they undergo screening for lung cancer with a low dose chest ct scan.