Bump on my face

I was looking in the mirror this moring and I noticed on my chin it was a little sore in a certain area, I have this before, it is a red bump that is full of whiteheads and lasted for 2 or 3 weeks
I don't really know what they are and I am getting weirded out because it is my 3rd...I try pushing it and afterwards the skin in the sore area becomes white
As a warning it is few days before my scheduled period so maybe that has something to do with it