Inflammation

Hi,
I would like to ask. I have small inflammation at the top of my labia majora, it is slightly red, a slight bump under the skin (only noticeable when I apply pressure) and is only a bit painful when I touch it and there is no irritation or itchiness. It has been there for about 3 days with no changes. Could this be an infection or a pimple or could it be something else?
Thank You