I got a fever 2-3 days before my period and i usually don't. some kind of infection?

Yes: A fever before your period may be a sign of infection, but may usually be accompanied with other signs such as abdomen cramping, nausea, vomiting. If Fever is really high like around 100 and you have symptoms like the one above you will need to seek medical attention.

Could be...: Fever is a signal of something is not right, most of the time an infection. It might have nothing to do with your period, depending on what other symptoms you are having. At your age and most commonly it is related to a virus and it resolves on its own in a meter of a few days. However, I cannot give a more accurate answer without knowing what other symptoms you are experiencing at this time.

Possible: although you do not usually get a fever sometimes your period can elevate your temperature. Is your fever persisting? What other symptoms do you have? If the fever has resolved and you feel ok probably you can leave well enough alone. However if symptoms persist you should bel seen.