Make sure you don't let it dry out, keep it moist with olive or vitemin E oil, it won't come off properly in the next two days because henna goes through several layers of skin.
I don't mean from when you did it, I mean from now onwards don't let it get dry, make sure its as moisturised as possible because it will fade better then :) x
When I had a henna flower on my hand, I wasn't allowed it at school so we put olive oil on it like every hour for two days and it was nearly gone. Not gone completely but you can't expect that but it had faded a lot and blended in with my skin sort of. What do you work as? You could always wear gloves x