I'm normally so careful in the sun, but I missed a patch on my back about 6-8 weeks ago in the intense heat and got a bad burn. It was very red, itchy, and it peeled at the end. It healed after a week, but I still have a patch of discoloured skin on my back. It's just a few shades darker than my skin. I so rarely get sunburn I don’t know if it's normal. Is it normal? Will it go away? Should I be getting it checked by a doctor?