June mamas who work in schools?

Nan
Any June mamas out there that work in a school? I work full time as a SLPA and have a full caseload of nearly 60 students. If I have to use a sick day, I am not provided with a sub and it is very difficult, if not impossible, to make up all of my sessions, due to my crammed schedule, and the fact that I work in three different schools. That being said, I have some complications and will require doctors visits 2x/ week to undergo weekly ultrasounds, non-stress tests, checking my sugar and prenatal visits. These appointments are scheduled during the times they have available and I have little say in when that is. I asked for the latest available appointments. I just got my list and the majority of them will require me to use two half days per week starting at 32 weeks, just two weeks from now. I'm worried about whether or not they will be able to accommodate me. I also do not have sufficient sick time accrued to cover me because I am in my first year. Should I just take maternity leave early/ unpaid to avoid causing problems with compliance? They would likely try to find a sub at that point so that students would not miss services. I don't know what to do, but I also don't want to stress myself out trying to carry out the impossible. Suggestions?