I am very anemic. could i have von willebrand's disease and not know it?

It's possible. : You don't mention if you are male or female. Women with VWD who have menorrhagia (very heavy periods) can develop severe anemia either acutely due to blood loss or more slowly due to iron deficiency, yet think their periods are "normal". Men on the other hand would generally recognize the amount of blood loss required to cause this as being abnormal.

Unlikely: There are many causes for anemia. Von willebrand typically does not cause anemia, but does cause bleeding: typically nose bleeds, heavy periods, and surgical bleeding. If the bleeding is severe, certainly anemia can result. But there is probably some other explanation for your anemia.