Well that was stupid! Providing it’s just a speeding ticket, you got real lucky. An alternate choice for the officer would have been to charge you with dangerous driving (usually once you exceed the speed limit at an unreasonable rate), and that becomes a criminal offence under the Criminal Code of Canada , essentially the same thing as a DUI. That would be exceptionally bad for your PR status.
Consider yourself lucky and think twice next time. It would be a real b*$&h to find yourself loosing your PR because of a speeding ticket.