VX
Mercury is tricky because mercury hides in your body and is hard to detect. I'd also advise getting tested for the excretion of heavy metals, through hair analysis (from a naturopath), so you have a baseline to compare in a year after fasting etc.
When many people initially suffer from mercury poisoning, if the source is still there they often suffer mercury retention (they are excreting almost no mercury at all). When they have the source of mercury removed (ex. mercury amalgams), their body starts to dump the easy-to-clean mercury at a higher than average rate for 6-9 months. Later, your body then starts to excrete mercury at the "average" rate for people.
Unfortunately, mercury hides and it looks like you are mercury free but hidden sources of mercury in your body can then cause problems for you 5-10 years later. It can contribute to giving you MS or other neurological disease, Candida, and more.
To excrete hidden sources of Candida, you'll need to either do chelation or perhaps fasting. You can tell, through hair analysis, whether your body is eliminating the hidden mercury because you should be excreting a high than average amount of mercury again.
Personally I'll be doing a little bit of both (I believe a little fasting in general is good), but relying on the Cutler protocol of chelation to do most of the work since many people have experienced good results with it. And I don't want mercury to haunt me later in life.
Anyway, using a hair analysis is a really good tool for determining how well your body is currently excreting mercury.
PS. Before chelating, make sure you've removed all sources of mercury from your dental work first. You probably have, but I thought I'd check.