Blood stains are one of the most steady and difficult for cleaning stains.You can manage to remove the main part but the rest will absorb very fast in the fibres of your carpet.It is always hard to remove such spot.You are rubbing and it always stays there ,just changing its colour -from dark red,to light red and after some cleaning it will become dark yellow.There are really strong detergents nowadays.But these are special detergents which you may not have available at your home.In spite of the steadiness of this spot when you have it on your carpet it is good to act in the really fast.First use the shampoo method but with more hot water.Rub untill the stain change its colour to ligh red.This is the first phase to remove the stain.Swab up with a dry cloth.Wait for some minutes and wipe again with a spongue.Do not rub too hard ,not to damage the carpet and of course use rubber gloves.Repeat again the procedure and rub untill the stain change its color to yellow.If you do this third time there will appear a damage of the surface of your carpet.This is all you can do for the moment.After this you can call us to remove the stain at all and to clean your other carpets.Have in mind that it is not good to wait to long before you call a cleaning company.