I'm currently 30weeks pregnant, if I divorce with my husband now, will I need to forgo my 4 months maternity leave at work?

It won’t affect. I was not married during the time of my daughter’s birth. And I can still enjoy 4 months of leave . But I’m not sure if you can still enjoy the baby bonus. But normally divorce takes around 3-4 months to finalise. So I suggest you register everything before applying for a divorce.