26 weeks pregnant. The last 6 weeks I've had horrible congestion in chest causing a constant cough. Common? I have no other symptoms of cold. No fever, vomiting etc. Just constant chest cough and irritation. I can hear stuff when coughing but rarely get

Yes, . Yes, i agree with you, you should be more concerned. Please see your doctor again or get a second opinion. Constant cough for six weeks during pregnancy needs a complete evaluation. It is very important that this be completely evaluated. If you have fever, shortness of breath, or chest pain then you would need to go to the er.