One it may very well be your medicine. Look at the package insert for side effects. I took femora briefly and I had a chronic non productive cough. Beta Blockers for high blood pressure will often cause a cough.
Just because you had cancer doesn't mean you might have other health issues that could be causing the cough. If the cough persists more than lets say a month with out improvement at least your primary care should look into why forgetting the cancer dx. It could be unrelated.