Left muscle pain, left chest pain and fever?

Flu?: You sound like you have a flu-like illness. More serious infections can cause this too. If your health is otherwise good, i'd suggest drinking lots of fluids, tylenol, (acetaminophen) rest, and give it a day. If you're not getting better or have other health problems, it's time to visit your doctor.

Pain and fever: There are many things that can cause pain, muscle pain and fever, the most common are viruses. These are treated symptomatically with meds such as acetomeniphen or ibuprofen, however, if the symptoms persist consult your physician.