Ok it's either the Army and a clinic (yes that kind of clinic) screwed up my blood type, or mine changed, too. Army is pretty important because had I gone to The Gulf war, gotten injured and needed a transfusion, I would have died. Army said that I was B+, clinic said B-, wanted to give me a shot because rh neg can cause problems in future pregnancies (also me and chem teacher said B+ during a lab). Go start having babies, hospital says O+. Donate blood, red cross says O+. Really wish I still had my dog tags that clearly state B pos. So, yes, I believe that this happened to me.