Ay, usually kasi it depends sa company mo and sa labor laws, pero most of us try to start our maternity leave around 4 weeks bago ang due date para makapag-prepare ng bahay and sarili. Pero if you want to work longer, pwede naman, basta sigurado ka na safe at comfortable ka pa rin. Best thing is mag-check ka sa HR mo or sa employment contract mo para ma-confirm ang exact dates and benefits you're entitled to, bawat company may different policies eh. One of my mum friends, nag-start siya ng maternity leave 2 weeks lang bago magbigay, pero she was managing office work from home, so it really depends sa gusto mo and kung kayang-kaya ng katawan mo!