If your blood is positive , it means that your blood contains Rh antigens with the presence of a protein called the rhesus (Rh) factor. Antigens are markers on the surface of a blood cell.
The Rh factor is a protein that can be found on the surface of red blood cells. If your blood cells have this protein, you are Rh positive. If your blood cells do not have this protein, you are Rh negative. During pregnancy, problems can occur if you are Rh negative and your fetus is Rh positive.