You can either call in and ask them to schedule an appointment 1-2 days before your EDD and 1-2 days after your EDD instead of 4 days, or just wait till you experience contractions then call your the delivery ward. Depending on each pregnancy, your gynae will be able to advise should there be any emergencies.
For my case:
EDD 26/12, scan on 21/12, gynae wanted to induce on EDD but cancelled cause he was busy lol haha. I was asked to go down to his clinic for a scan on 28/12. Scan in the noon, induce at night due to low fluid 😅.