Continuous leave for more than 5 years in job

Hi Sir I work in one of the schools in Delhi Cantt. I came to Australia with 3 years of extra ordinary leave and NOC(w.e.f. 26 October 2012) as my husband works here in Australia. Then my leave was extended for 2 more years on medical grounds as I was taking fertility treatment and had a surgery because of that in Australia. Now I have to join my job on 26 October 2017 according to CCS leave rules 12(1) but by the grace of god I have a conceived and is 5 months pregnant and my delivery is due this December(2017). Is it possible for me to apply for maternity leave (from 26 October 2017) in continuation of extra ordinary leave. I want my delivery to be done in Australia as my husband stays in Australia and I have been taking treatments from here and conceived after 3 years of trying in Australia. In case if I join my job on 26 October 2017 and ask for NOC to deliver the baby in Australia, I believe it would be hard for me to get. Is there any other way you can suggest so that I can save my job and deliver here in Australia. I want to join the job after my maternity leave finishes. Please advice. Thanks