Suggest Remedy For Pimple In The Middle Of The Chest

Hi, I had a pimple in the middle of my chest and it wouldn't go away. I never used to gey chestne butn now it seems I have some. I had that one pimple and it wouldn't pop or do anything so I took a apir of nail clipers and I pulled out this sac like thing filled with white pus. Of course its very small. Now it was like I had a small hole in my chest but the solid-ish white sac is gone. Is that normal? Is all pus under pimples really in a little sac that can be pulled out?