My blood type has always been a "sensitive issue" in my family.
Both my parents are A+ (and so is my sister) so when I was born, they just told the doctors I should be A+ because they both are AND THE IDIOTS PUT THAT IN MY MEDICAL CHARTS WITHOUT CHECKING. So I lived my whole life with that in my records and all the times I had blood drawn, no one thought to check or change it. When I gave blood at 18, I found out I was O+.

It totally freaked me out--I thought I had been adopted or switched at birth or something. I didn't think it was possible to be a different blood type than
both your parents but my mom researched it and told me to get a grip, it can happen.