Once. Won't ever do it again.
Me, too. I got raked over the coals for doing this, last year. I shot one doe....and didn't see her go down. I ended up shooting another.....and though I'm not positive on whether or not the hit was lethal.....I didn't recover her.
I had temps working against me. My advice is.....if you don't see the first one go down......keep your arrows in your quiver.