21 Days clearance is about right.
Rule of thumb for mimium break between cycles is: Time on + PCT = Time off.
ie 10 weeks on, 4 weeks PCT. 14 Weeks break required.
This is not science, only blood test will reveal whether you have recovered or not, and from your post i can guess you have no intentions of getting bloods done, and also have no bassline tests either.
For a clomid only PCT i would of ran 100/100/50/50