I Noticed A Small Pea Sized "cyst" On The Inner

I noticed a small pea sized "cyst" on the inner side of the labia minora. It was moderately painful and uncomfortable if touched. Tonight after a shower I was looking at it and noticed a small red mark. I very gently squeezed it and puss and blood easily came out. I cleaned it again in the shower and the lump is still there. What is this?