Well, I wrote it last night, and today I wore pants and long sleeves, so it wasn't really an issue. But honestly, I don't think it would be a bad thing if someone were to see it. It might give them some encouragement.
But my hardest struggles are usually at night. So if you were to write it at night, then you could just wash it off in the morning, if you wanted. Whereas a cut, unfortunately, you can't wash off.