Coughing

I am under thirty, and quit smoking 3 months ago. I was coughing alot, and decided to quit. I feel like I was coughing for years. I quit when I was pregnant, and after a few months the cough went away. I started up again recently and quit after a year (three months ago).I am still coughing. Not as violently, but off and on all day, esp in the morning or after I eat. I sometimes cough up clear phlegm. I have no trouble breathing, and my chest dosent really hurt. I am scared that I am coughing so much because I might have cancer, or that the coughing will hurt my lungs and cause something else! I am also a partial hypocondriac and find myself spending all of my money on tests. Do I need to go get any tests done?