I would keep offering him food every 4 or 5 days. I take it you are feeding him live? If the place near you has frozen prey, you could try getting one, thawing it and warming it up, and then leaving it in the cage with him overnight. Some say that is the only way their BP will eat... when left alone overnight. DO NOT leave a live mouse in there over night, or anytime unsupervised or for more than a few minutes, as it can harm the snake if feels the need to bite or claw the snake.
I'd also pick up a cheap digital kitchen scale at Walmart, amazon, ebay, etc... then you can weigh your snake when he goes on a hunger strike. I believe the general thought is that if the snake isn't eating, but really losing any weight, there isn't a need for panic.