I am sick do I need to call off
When servicing you are in command of your own schedule. You are an independent contractor and while a notification is greatly appreciated, it is not necessary. Keep in mind that dropping or not showing up to intervals can decrease your commitment adherence. If it is absolutely necessary for you to stop servicing release your intervals as soon as possible.
Tip: Try to swap your intervals first! It will not hurt your CA if you get your intervals picked up by another agent.