maternity leave

Hello
My husband and I would love to have a second child soon. Our only child is turning 6. I currently work 25 hours a week and I have had the same set shifts since I started my job a year and a half ago however I am a casual employee. My question is will I still be entitled to some maternity leave being only a casual? Im not sure who to contact about this, centrelink? Although my husband earns good money im not sure if we could survive on only his income while im off work. As we are paying off alot of debt at the moment. Thanks in advance