No, medical request is send ONLY after you passed your eligibility :
Determining admissibility
Once the office has determined that an applicant is a member of the Canadian Experience Class (R87.1), the principal applicant and their family members, whether accompanying or not, must complete medical examinations, and pass criminal and security checks.
http://www.cic.gc.ca/english/resources/tools/perm/econ/cec/decision.asp
So, congrats