I have a sore bump filled with white pus. I popped if IT AND IT CAME RIGHT BACK.

Body fighting infect. Likely your body is still fighting a bacterial infection that has not yet cleared. The white pus is actually death white blood cells that have been trying to kill an infection. This is actually a completely normal response. But if you want you visit your doctor and he or she might be able to determine if you need any topical antibiotics.