Hi, I had a potential blood clot but a chest ct came back clear. I still have chest pain and upper back pain as well as shortness of breath. What could this be. They said it was potentially a muscular or skeletal pain but I get pain on my left side especially. They suggested pain killers, I’m not convinced it’s a muscle strain nor could they tell of an infection. X-ray and ecg are fine, I still think there is something wrong. I am short of breath and my left shoulder feels achey. I have a small cough and cough up a little phlegm if I cough too much