You Know the Days When What You've Always Thought Was True Turns Out Not to be the Case?

On Katherine's birth record from the hospital, her blood type is listed as B+.  Not O+. I should have known to check or do a home test because we've had this happen with the other kids, and honestly still don't know the correct blood types for all the kids because we've gotten so many different classifications over the years.

I. Am. Annoyed.