Freckles on inner labia majora?

Hey y'all...so 4 years ago I noticed two dark spots on my left inner labia majora (the size of a pin prick). I thought they were burst blood vessels or something. But the other day I noticed that one is them has grown to be the size of a pencil eraser head. It's not raised or anything but what a weird place to get a freckle... and why is it growing and changing shape? Can you get melanoma on the labia of your vagina? Does anyone one else here have something similar happening to them?