I know how to delay one? eat some SureGel (its in the jelly section). Eat a third the box with water, it sucks, but ive done it four times. It is fruit pectin which is in all the cleansing drinks for 40 bucks only it is 3 bucks. this will come up sometimes (1 out of 4) diluted.. which will give you an extra 3 days to clean up... hope you get that job