My blood type is o (positive), does that mean I can only recieve o (positive or negative) in case of an emergency?

O Positive. O + blood type means you have the rh antibody. If you receive o negative blood, which has no rh antibody, you are ok. If you receive o+ blood, you're ok. But if you donate blood, there may be a problem to the recipient, if they have negative blood type. Any transfusion is preceded by a cross match wherein the two bloods are checked for compatibility to lessen the risk of transfusion react.