When should I take maternity leave

I get 12 weeks unpaid maternity leave at my job and I’m thinking of starting my leave before the baby comes but I also don’t want to take too much time off because I want to be with my baby for as long as possible before I have to go back to work. I work in a real estate office with the majority of my coworkers being guys so I’m a little nervous about my water breaking at work in front of all of them. I also just want a little time to myself because at that point I feel like I’ll need to relax and start preparing for baby and not be at work stressed all day. How do I know when to start my leave if I did decide to take it before she came? My mom had all four of us 2 weeks late and my sister had a couple of her kids late so I feel like my baby may come late too. So I don’t want to take my leave at 39 weeks and not have her til 42 weeks. I’d like maybe a week to myself max before she comes. I know there’s no way to tell when a baby will come but what’s your experience with it?

Edit: sorry I’m a ftm and I figured that your water breaking just happened out of no where lol.. 🤦🏻‍♀️