A low grade fever that won't go away normally is signaling your body has an infection that it cannot thwart off. You should see a doctor to see why your body cannot fight off the infection, or to see what infection it is. Could be a sign that something serious is oppressing your immune system.
All fevers should be closely watched. A low grade fever is not usually something to be worried about but if it persists you should contact your Primary Care Provider and ask them what measures you should take.
Any kind of fever comes from an underlying condition or illness. The fever doesn't have to be treated. It is a good idea to find out what is causing your fever because it could be something serious. Your doctor will probably tell you that if fever doesn't go away in so long a time, to come see him.
A very low grade fever in the absence of other symptoms is sometimes considered normal. The best thing to do is go to the doctor and have it investigated. There are illnesses that manifest first as low grade fever and your doctor can best locate the cause.
Yes, can be sign of a progressing infection. Also could signify a gallbladder problem. Need to go see a doctor they will probably prescribed broad spectrum antibiotic as a precautionary. You can also take acetaminophen or Motrin if it bothers you. But do not take these all the time because as a temp is your body's defense mechanism.