Yes, something definitely could be wrong if you think you have a fever
and it has been persistent for over a week. Definitely a fever may last for different durations depending on the clinical situation, and may not resolve itself if the cause is serious. A fever is generally a manifestation of systemic inflammation. If there is persistent inflammation for a variety of possible reasons, you may continue to have a fever. There is no fixed time for how long a fever should last.
It also depends as to what your symptoms are and what you define as a fever. A fever of 100.4 is generally what is considered significant, and depending on your symptoms maybe due to a virus, a bacterial infection, drug related.
It is of the utmost importance that you make an appointment to see your primary care physician
to discuss your situation. Your doctor
will be able to ask you questions about your clinical picture in depth, perform a detailed physical exam, order necessary lab tests to check for inflammatory changes and for other alarming values. Depending on these results, your doctor will be able to treat you appropriately, possibly with antibiotics or with other therapy.