For us, myCIC was updated to say "You passed the medical exam" 4 business days after the medical was completed, and ECAS also updated to say "medical results have been received."
Do you know if the clinic that you went to uses the e-medical system? That would likely make a big difference in turnaround time as e-medical allows them to electronically submit straight to IRCC with minimal turnaround time?
I also wonder if it depends where your application is at the time of the medical? For us the medical was done on March 1st, and the file transferred to Sydney, Australia only on March 12. So the medical was requested by Sydney, Canada and processed by Sydney, Canada via the e-medical system -- I wonder if that had a lot to do with the speedy turnaround? If your file got transferred to Aus while medical was in process and the clinic didn't use e-medical, it might take quite a bit longer for it to get to the right agent and updated across all systems? That's just a thought, I'm not really sure (aside from whether e-medical is used) what could impact the speed with which medical passed is registered to your online account...