Questions on maternity leave

I'm wondering when I should take my maternity leave. I DON'T want to go into labor at work. I also want to wait till after new year to go back to work. Baby is due Nov 2. I have some vacation time saved up but only have 6 weeks maternity leave. I'd hate to use all my vacation waiting for baby to come and have less time with him. But I have to use my vacation before the end of the year or lose it. Right now I have exactly enough days for my vacation and my maternity leave before the new year. Once the new year starts I planned on taking 2 more weeks of vacation. Worried that baby will be late and I'll lose vacation or baby will be born early and I'll run out before the new year. Any suggestions?