I am also of native american heritage from my grandmother. I descend from the cherokee. Interesting enough I have always wondered but I to was born with a birth mark on my back instead it is in the shape of a swan. I have always been told in my family that swan shows some significance to my family personally because my great grandmother's name meant swan. I don't know if it means anything else, I've had it since my birth and it's still there in a visible shape of a swan.