Maternity leave

So as my due date is approaching my job is asking how many weeks I am taking off 😩 they do not give any paid maternity leave but I am able to have my position when I return if it is less then 12 weeks I believe. So I am thinking about taking 8 weeks and then returning part time for a few months and then back to 30-40 hours a week. I would love to stay home with the baby but I also love my job and I am only 22 so I need to continue growing in my career patch. But I really need to start planning with my job about the amount of time I will be off. I also have to work to pay bills so it’s not like I can be off too long 😫