Hello, Welcome to Healthcare Magic. I have read your question completely and understand your concerns. Your symptoms are unlikely to be due to penicillin. Your tight chest and phlegmy cough could be due to infection travelling from your throat into your airways or lungs. To get rid of the tightness in your chest you would need bronchodilators like Salbutamol either as an inhaler or as a nebuliser depending on the severity of the symptoms and on the examination findings. Hence, I would advise you to see your doctor for a follow up. You may even need another additional inhaler called a Steroid inhaler, for e.g. Beclomethasone or Budesonide inhaler. Your doctor may even prescribe an additional antibiotic if he thinks you are not quite well. I hope this answer has helped you. Thank you. Regards Dr Sunita Sayammagaru