A stall or plateau is considered 4-6 weeks or more with no loss of lbs or inches. As it has only been 5 days, I would not consider it a stall. Your body is probably just adjusting to your >20 lb loss. It is not uncommon to stall for months without loss. Have you been measuring yourself?... it is very possible that you are losing inches w/o losing lbs, especially since you are exercising and building muscle.