Weird Mark on vulva

I am 22F and two years ago I went in to see my gyno because I had a very dark purple mark on my clitoris. It was very small(about the size of half a sunflower seed). It was underneath the “hood” part. She said it had something to do with my veins and not to worry. It has been almost three years since I first noticed it and it is still there. It itches and hurts on occasion. Is this something I still don’t need to worry about? I thought it would go away by now if the vein just needed to heal. But I’m not really sure how it works.