Not really enough info here to make a good guess. But AWAYS, when in doubt just back out. I was a deer search tracker for a few years, and have seen a lot of blood trails. Best advice I can give, unless you now have found good blood is to back out and go in at first light. Check the hit sight for hair. What color is it? Then try to pick up where you lost the blood trail. Blood will show much better during daylight. Some good advise already given in previous posts. Good luck to you.