You should get a form 884 in your email within days. It will contain instructions as to what to do for your GP/specialist. After the relevant test is done, the GP/specialist will forward the result directly to DIAC. A few days later, you will see "completed" and submitted to DIBP. If immigration (Medical officer of the commonwealth - MOC) is happy with it, the status will remain as "completed" and "submitted". If the MOC is unhappy with it, the status will say "incomplete" and "not submitted" within a few days.