Maternity leave length?

I'm a senior in high school and the timing of my pregnancy is very unfortunate. Don't get me wrong, I'm excited for my child to come into this world, but he's due at the beginning of May, which is not convenient at all!!! šŸ˜– The month of May tends to be an extremely busy and important month for any high school senior who's planning on graduating. How soon could I get back to school in time to take my finals? Will I be able to even go back at all in the month of May? I really want to stay on track to graduate, if I can't take my finals on time I may not be able to walk with my class at graduation. Baby is due May 3rd, last week of school for seniors is May 18-22 which is the week they will be taking finals.