Cat scan

So for the past year or so I’ve been experiencing chest pain, and a persistent horrible sounding cough not to mention a swollen tonsil. I’ve had numerous X-rays on my chest and blood work done and nothing has even come up. My doctor has booked me in the get a Cat scan done to see if I have cancer. I am freaking out. WhAt are the chances? Anyone else ever experience these and it not be cancer? What was it if you did have it?