You’ve come to the right place.
We have an article on how to set up a maternity leave policy and it even contains a sample policy that’s free to download. What I might recommend:
1) Print the article
2) Download and print the policy example
3) Mark up the policy in a way that makes sense for your company, for example, might they offer paid leave, or only unpaid leave?
4) Present the information to them to mull over
5) (Be patient, they may want to consider options)
6) Schedule a meeting a few days later to talk through your maternity needs and see if that helps them get the ball rolling.
If they have fewer than 50 employees, they’re not required to provide leave, but many employers want to keep their team members happy — at least by providing unpaid leave. Approaching it from your own needs, may help them think through what they want to offer for all.
Good luck to you and congrats on the baby!!!