Our blood type does not match?

the A is co-dominant to B, and both A and B are dominant to O. So if your mom is AB and your dad is B then your blood type must be AB or B or A. there is no way your blood type can be O because both parents must carry the O allele for that to occur. You should check your parents blood types again just to make sure you have the right information.

You're right, that is strange. AB and B blood cannot produce O offspring. So you might want to be asking you mom that question.

Autumn, your blood group doesn't matter a fig. Your parents are the ones who loved you, fed you, sheltered you, and nurtured you. Even if you are not their biological child. I was adopted, and my adoptive parents are my family, they are the ones that chose me, and loved me enough to raise me as theirs.

Remember the past is history, the future is mystery, today is a gift, that's why they call it the present.

You may wish to consider your grandparents' blood types. Sometimes, genes don't express themselves until a generation after, in this case, perhaps the O- blood type.