Chest pain in left side. Please advise.

I have been suffering from chest pain for about 15 days now. The pain is in the left side right under the breast. The pain travels to my back when I lay down. I can't take deep breaths because it causes pinching pain. I cannot sneeze as well. I feel I have mucus in throat though I'm not coughing much. Last year I had severe cough for about a month. I consulted a doctor locally who advised me a Chest xray and HRCT. However, reports of both the tests came normal. I also got my CBC test done, which is normal again. The doctor prescribed me a pain killer with paracetamol because in initial days I had fever as well. Now it's gone but chest pain is there and it's only worsening. Please advise.