How do i know what it is it look like an umbilical hernia but it hurts and do i need to see a doctor?

Yes, see a doc: An umbilical hernia can be an obvious large bulge at the belly button but can be a small, barely palpable defect. The small defects can be painful if a portion of the omentum gets stuck and gets inflammed. A loop of intestine can get stuck in a medium-sized hernia and become blocked or dead and create a surgical emergency. If you think that an umbilical hernia is possible, please see a doctor!