Temps are dropping... sometimes, BPs go on hunger strikes during the winter months. Females especially may do this.

Can I ask how long you've had him/her? Is this the first winter you've been through with him/her?

I agree, leave the snake alone, don't get him out for handling or anything for another week, make sure your temps and humidity are spot on---again, things are changing in the atmosphere---and try again next week.