I have an appointment message in four days.

Notice will be given only 1-2 days before the exam, just like you have to take subject 1, subject 2 and subject 3.

Hello, after making an appointment for Subject 4, you will receive a message informing you to take the exam within 1 days. If the appointment fails, a text message will be sent to inform you that you need to reschedule.

Yes! But there will be mistakes from time to time, so you'd better check online.