No need to fear "chromium/cobalt leakage" - that is not how it occurs, and surely not in a time as short as 3 weeks. Your implant was not "metal on metal", but rather the more traditional metal/poly - and probably the insert in the pelvis is titanium.
The metal poisoning that some of us experienced was when a cobalt liner was used (without poly), and the chromium and cobalt wore against each other over time (4 years or longer) releasing minute bits of the metal into our tissue. By 2010, virtually no surgeon was using the combination any longer as the problems began to show up, first in the UK & parts of Europe, then in the US.
Relax, rest easy, and good luck with your revision!
Sue