If you have a good flashlight, I'd go now. Over my 30 years of tracking deer I've come up with the rule of thumb that I don't track a deer for 30 minutes after it's been hit and then if I think I have a good hit I follow the blood until I find either the deer or where the deer bedded down. If I even think I may have a marginal hit I wait 2 hours, then track. If I find a bed without a deer, that means the deer had enough strength to get back up with whatever hit I made and THAT means I need to back out. Based on your OP, 3+ hours is plenty of time and the deer should be dead by now and the more time you wait, the greater the chance of you finding a coyote tore up deer. If you find a bed without a deer in it, at least you will have mucked around enough to give the coyotes a bit of pause to hunt for a meal elsewhere. Good Luck!! Let us know how it goes!!