The dark line on my belly from when I was pregnant has turned into a something that I can scratch off. Why?

Answer 1

The linea nigra [ black line ] is produced during pregnancy by the hormones in your system. Once you no longer produce them, the dark skin cells die, just like all the other skin cells; and flake off.
It will come back when you have another baby.

Answer 2

thats just the skin regenerating itself.As the skin flakes the mark is getting lighter and lighter