It sounds like you are doing everything right. I did an 18 day Master-Cleanse for my first one in early July. Now I am doing Colosan and Dr. Clark's parasite cleanse. I've been on it for 3 weeks now and haven't passed anything.
With parasites everyone is different. For some people it takes a day or 2 to start seeing some, for others it takes weeks.
If you follow the Master-Cleanse by the book it says to not take anything else. I am planning another Master-Cleanse and will use the Colosan instead of the SWF (Salt-Water-Flush) and will continue on with the maintenance protocal for the parasite cleanse. The key is not to put any toxins into your body or anything that needs to be digested.