Cutting scars.

I'm several months pregnant and it just hit me that there'll be a point where I'll have to explain to my child/children why I have scars on my arm. I'm a Christian who went through a dark period of time. I know I'll have a couple of years until then, but what is a good way to communicate what happened but bring it back to the Lord? This would also help with future questions from other people too.

thanks.