What Causes Reddish Raised Itchy Bumps On Skin?

I have a huge red raised bump that s shaped in a circle form that has a dot in the middle that I squeezed and pus came out until there was no more. It still hurts a little and the bump is very slowly going down. 2 days i was itching in that spot wearing leggings and then yesterday this appeared. I want to know what is this? Also I have been getting small tiny filled pus bumps that are already ready for me to bust and when I bust it, it hurts a little and is a little raised until the end of the day it goes down. I am very concerned about this and would like to know if I need to see a doctor about this.