You should remember that it likely took years for the mercury to build up in our systems. It's going to take quite a bit of time to get it all out, probably years. That being said it varies a lot from person to person. It depends on how much you have in your system, and how efficient you are at removing it.
How do I know I'm making progress? I'm feeling much better. Many of my symptoms have lessened or disappeared. My reactions to chelating have become less and less. My reactions to breaking the candida diet have become less and less. I'm eating a bag of oranges right now. Before, that would have made me feel awful for days. Now my reaction is tolerable.
It took me about 6 months of chelating before I felt noticeably better. It's been slowly getting better and better since then. I feel like I'm reaching a point where I won't need to do this anymore. I'm not there yet, but I'm hopeful. Hope is not something I had much of before I began the diet and then chelating.