I want to fix the problem I created
What problem did you create?
I neglected to take my dog to their vet checkup.
It's good you realized you made a mistake you, because now you can correct it as soon as you can. It will be best for your dog to take it to the vet.
I know.
That's good. You should call the vet and try to reschedule the appointment. That way you can be sure your dog is healthy, and you will feel better.