I'm glad that you found the deer, it is a shame to have them go to waste.
This is a good lesson to learn. No matter what you think you saw when you executed the shot... perfectly broadside, quartering away, etc... and no matter where you think you saw the arrow hit... perfect double-lung, a little high, a little back... you'll never know for sure until you find the buck.
But the next best thing is to find the arrow and let that be your guide as to how to proceed. Any indication of gut shot, regardless of what your eyes told you... wait at least 4 hours. If that means a sleepless night, so be it.