Three blades dosen't always mean more blood. More blood doesn't always mean you'll find the deer. No blood doesn't mean you won't. Where you thought you hit, isn't always where you hit. Sometimes a bad hit results in a short tracking job. Sometimes a good hit, looked like a bad one.
Point is, things happen so fast you can't always be sure. Once you make the shot, it's your job to do the best to recover the animal. There's some good tracking tips given above. If you do that and still don't find it, as said, nothing goes to waste so get back on the horse and keep on riding.
The bottom line will always be, a well placed razor sharp broadhead is what will give you the best results.