YES. Maybe both of your parents are half-Rh positive, but not a full-blown Rh positive. Your parents will have 25% chances of getting a Rh negative offspring (Out of 4 children, only 1 become Rh...
It depends. There are 8 main types of blood. A, B, AB, O, A negative, B negative, AB negative, and O negative. The 'negative' means you do not have the RH in your blood. The origin of RH negatives is...