Need advice with agencies

Hello,

About two weeks ago I just got my first agency job. I am unsure about how to make this work. I wanted to work for an agency because I need flexibility as I will be going taking classes for my RN and I need something flexible.

My problem is not working nights or any shift, its what days I can work. They only call me when they have work, so its not exactly the most reliable job. I was wondering, what have those who worked with agencies done to fill in for the time that you were not called? Do you work with multiple agencies, or work somewhere else part time? I have thought about trying to work with multiple agencies, but my problem is I do not know if I have work or not until sometimes 1pm that day for the next 2-3 days. I really do not want to work weekends, as I hardly see my wife otherwise as she works a 9-5 job and I am working nights.

Thanks!