Had a heavy cold last week, no fever or real cough. worst gone. now have sore throat, producing brown/red phlegm, slight tiredness, shivers, no cough.

See your doctor: It is common to develop a bacterial infection like pneumonia after a viral respiratory tract infection. (I.e. A cold) This usually occurs shortly after the viral illness begins to improve and requires antibiotics. Symptoms vary but include fever, chills, chest pain, productive cough, sore throat, shortness of breath, tiredness, loss of appetite, etc... You need to have a doctor examine you.