O+ is the most common blood type. B+ is less common. No need to worry! The reason most doctors check for blood type is to see if the mother has a negative (-) blood type. When mom has a negative blood type, and dad has a positive it can cause something called RH disease in the infant. The doctor will give the mother a treatment injection sometime before birth so that her blood doesn't try to attack baby. It's ONLY if the MOTHER has a negative blood type- you're fine, you're positive, don't worry.
Everyone has a different blood type, either A, B, AB, or O, all pos or neg. It doesn't really mean anything but they need to know it because some types can only receive certain other types if you need to have a blood donation, or if you ever donate blood. Also your baby will get either the mother or the father's blood type, and if the baby has a different blood type than you than the doctor will give you a shot at some point just to make sure your body doesn't think the baby is a disease or something attacking it. My blood type is O+, I think maybe O+ is the kind that is considered the universal donator, as in every blood type would accept that if they needed a blood donation. Blood type is just something everyone has, it's like saying you have blue or green or brown eyes except that each kind doesn't always mix well with other kinds.
There are four blood types: O, A, B, and AB. Each blood type is also either (RH factor) positive or negative. O is the most common blood type, followed by A, then B, then AB. You have an uncommon but not extremely rare blood type. No worries though -- hospitals, clinics, and treatment facilities don't have any problem providing blood type B to people who need it.
The blood types are A, B, AB, and O which is the universal donor.
You have type B with RH positive. You can only recieve a blood transfusion from someone with blood of the same type or from someone with type O.