Needs cancer screening. My body to know?

Hi sir,last three years I got severe cough in 3 months of 12 months.I got consulted to pulmonologist every year,he did routine physical exam n tests like CBP,chest x-ray, PFT etc.. Investigations ,but all r showed normal,he writes some cough syrups and cough will come down.recently my mother was diagnosed with stage 4 breast cancer n under treatment now...Hence my question is my cough symptoms are due to cancer?My pulmonologist says iam unable to say about that.i want to know y iam getting severe cough in particular period of the year though all tests shows normal.if I have the risk of cancer whom to I consult n how to screen my body to know?I have no other problems,iam healthy in rest of things.suggest me tests to detect the cause of my cough n screen of cancer..Thank you..