I'm going to cancel these plans
Why do you think it's necessary to cancel your plans?
I don't feel like doing so.
If you have made your plans with other people, they may feel hurt by you cancelling, or worse, have costs incurred to them by your cancellation. I recommend you talk to everyone that is involved with the plan to see if cancelling will be okay with all of them.
I know my plans for the day. I'm going to stay home.
I usually want to just stay home alot of times as well, but again, unless everyone will be okay with you cancelling the plan, you should not cancel. At least make it so that the other people who will not be okay with the cancelled plan be compensated or be allowed to continue with the plan without you or without incurring more costs.