How do I cover my birthmark?!?

So I am of Asian Decent and we are fairly known for having whats called a mongolian birthmark. but whats odd is that it's only supposed to last 3-4 years after birth, and I've had this all my 17 years! right now I have to wait for a dermatologist appointment, but in the mean time; I have a modeling job soon and I need to cover it up! Any suggestions?