how long should a cleanse take?

Hi Everyone
Have been reading all your posts with interest.
Here is where I am at -
I have been doing the P&B cleanse (starting with 1 shake/day for a week then adding another - I now do 4/day). This I have been doing for 5 weeks now with NO mucoid passing through at all!!!
Is this normal... should I have a break... add something else... try another cleanse.
Please help as I am growing weary!!