If you have checked and rechecked your temps and humidity and they are within the ranges others have posted above and stay steady, the bp is healthy and no mites etc then just keep it that way and wait about 2 weeks and try again. If your temps and humidity are correct and your snake is healthy then your bp will eat when it's ready.
Mine goes off feed every fall/winter for about 6-7 mos. then goes back to eating like a piggy. My temps and humidity stays steady as a rock, doesn't matter, it's just what he does.