Should my foot hurt after almost a week since being stepped on by somebody else?

Stepped: Usually not. But, if it was hard enough, you may have an injury needing attention by a podiatrist or your pcp. It may be just a contusion (blunt injury) with residual pain. If it continues the same for another week and you can't walk on it, get some help. Try ice and rest. You might want to try some Aleve (naproxen) or Motrin also to decrease the soreness due to the injury.

Possible: The pain should at least be decreasing, if not i would have it examined and possible x-ray to rule out fracture.