First, bedding area has nothing to do with it. If there was a significant blood pool and trail to begin with then it is more than likely a lethal shot. You also stated that the doe went into thick bush so unless you are going to step on her, you are not going to find her in the dark (flashlights become useless in thick bush, if you've never tried one in such a situation, give it a shot for it's tough to describe the shadowing etc.). I would mark the spot where you last found blood and then also mark the spot where she went into the thick stuff (I always carry some blaze tape in my hunting pack). Wait till morning and come back with some help. With a lethal shot and with out being pushed she will lie down and expire. I had a similar situation occur a couple of years back. I looked for a couple of hours, didn't find the buck, it rained like hell that night, I couldn't sleep because I thought for sure I would loose him, went back at sun up, and found him. I'm sure I must have walked by him a couple of times the night before for he had lied down within some real thick bush (if I didn't notice a little white from his belly I may have even missed him in the morning). It is difficult to leave the search for a deer that you know is down but in thick bush it is near impossible to find it at night. Just talking from experience.