No, you don't. Koodo has billing cycles that fall on certain days. For your first bill, you get charged for the days remaining in that billing cycle ((monthly cost/30)*days left in cycle) plus your next month in advance. This is called proration.
As per the new CRTC rules, no carrier is permitted to charge you for a month after you cancel. If you were to cancel, you're only responsible for whatever you used up until the cancellation date.