I think you have to be careful if you are seeking out a chelation clinician. They have to really know what they are doing and they shouldn't remove heavy metals at such a pace that it will harm you.

You can naturally chelate through food and supplements - specifically algae and kelp. Dr.Terry Wahls has talked about this in her book (you will probably get some hits if you Google it). She also typically see's heavy metals in her clinical trials patients and finds that after 1-2 years they detoxify naturally.

You can also have your mercury fillings removed, but make sure you find a dentist who does it safely. And disposes of the waste properly!