Outstanding job! As others have said, sometimes perfect hits leave little blood for whatever reasons (and not the broadhead's fault). Just happens. Had that deer been liver hit, your waiting to take up the trail would have been very beneficial to you. When in doubt, back out...
Congratulations on your first deer. You did very good!!!!
One last thing, did you try to backtrack on the blood trail? Even when I see a deer fall in sight, I ALWAYS follow the blood trail. Each one is a learning experience...even those like yours where for whatever reason there wasn't much sign to go on. Again, congratulations.