I am O neg as well and canadian and have been told all the same things myself.
My brothers and I all have the same blood type(so Im guessing both my parents do as well)they call my brother asking him to donate all the time but I have only donated once,same thing with me-- I need all I have and I have low iron. I have been told that O rh neg is the only blood I can have.--- not that i ever plan on having a blood transfusion-- if I did i would take my brothers! Now that I think about it my brother has 2 mothers to his children and they both had a hard time carrying the baby's, I'll see if I can find out anything about their blood types.