Straight vinegar is great for blood stained clothing. Apply the vinegar directly on the stain and blot it with paper towels or some other absorbent material. When the stain is removed, blot again with a damp cloth and then launder as usual. Read on from www.happynews.com/living/cleaningtips/remove-blood-stains.htm.
I use a pet stain remover called OUT! this product can even remove set in blood stains because its enzymes action breaks down the chemical bonds holding the blood to the fabric. It is such a great stain release, that we use it on all of our laundry. It is found at Wal-mart in the pet isle, and also at most larger pet stores. :)