unexplained chest pain

Hi,
i was just told that my cancer has spread to both lungs.(see other posts) I have had a dry cough for 6 months now,chest and back pain that started 2 mo. ago and has gotten worse. the Dr. cannot tell me what it is from. He says the fatigue and increased shortness of breath could be related to the cancer but, the chest pain is not. he has no explanation for the pain. ( i wonder if he thinks its all in my head) The cough he has never been able to explain either.i talked to him this morning and he doesn't think its an infection of any kind and that maybe i should see a heart specialist. has anyone experienced anything like this? the cancer is not large enough to cause any pain yet. i have been taking tylenol 4 and ibeprofin 800 for it, but it has gotten worse and now i'm taking duladaid 2 ml. also. sorry for this being so long. thanks all. GOD BLESS YOU ALL!!