No. - IIRC O pos it compatible to be given to any blood type- so they want it. Not that it matters so much with Ab+ it means you can take pretty much all the reg blood types(there are a few really rare ones) also, people with O+ can only have O+ so the need for it is even more important to blood banks and stuff
At first I read this thread as: what's your blood LIKE... I was like, why do you want to know? And I don't know my blood type.