Sudden vagina birthmarks

I tried researching and found almost nothing. Recently, I’ve noticed about 3 small, light brown spots on my vagina. They look like birthmarks. I don’t have any weird symptoms or anything different down there. I’ve never noticed them before. What could they be? They basically appeared out of nowhere

Edit: no, I’ve never even gone to tanning beds. If it works the same, could it have been caused by series of X-rays? Or mri?