You were busted. Its hell to have that happen at day break but you were busted by a doe. It winded something that wasn't right or it crossed your path to your stand. Thermal currents and wind change are your worst enemy. I have never known a buck to keep blowing, they'll blow/snort one time and leave but the does can blow for an hour warning that something just ain;t right. Just like a barking squirrel. Good luck.

Bobby