That's great that you got your mom to use internet to ask a doctor a question.
It will usually take about a week, give or take a couple of days. Most of the time it heals by itself. However, there are some that will get infected by getting bigger and more swollen and become more painful. If this happens, your mom will take you to the doctor for real and maybe put you on antibiotics which will make the infection go away.
Hope you feel better soon.