That is an excellent question and one that is best answered by your primary care doctor
or another medical professional who can examine you and obtain a complete history and physical examination. Based upon the minimal history provided, it is difficult to know the exact cause for why you are having these symptoms, but there are some general conditions that may cause the symptoms you are describing. For one, it is possible that you were feeling the initial symptoms of the flu and that you are not having worsening symptoms from it. did you get a flu shot
this year? It could also be that you are having a bad cold as these are not infrequently symptoms that are seen with a cold. The pressure on the chest could be related to cardiac or pulmonary issues and sometimes these can be related to an upper respiratory infection. It is important that you are evaluated by a doctor who can best evaluate you and find out the cause of these symptoms and treat your symptoms appropriately. It is also very important that you maintain hydration while you wait to see the doctor as sometimes dehydration can become a very serious thing with colds or the flu.