I've read this thread with interest, since I was in school when my daughter was born. I really sympathize with you about the inflexibility of your situation, since what the other ladies say about the unpredictability of birth is totally true: I was fotunate in that my school administration assured me that if I couldn't handle my courseload, had a difficult birth, or anything, I could drop classes past the deadline. On the other hand, we NEEDED my student loan to get by, so I was praying that wouldn't happen!
And you know what? It all worked out -- so it is possible. I had the luxury of having my husband at home (he was laid off, then we decided he would stay home with our baby on a more or less permanent basis), and he could lurk outside class with her as needed. Still, though, it was possible to take her into class -- I had choice in what classes to take, so I picked ones with instructors who I felt would be helpful, and contacted them ahead of time. I missed three weeks of classes entirely after I had my daughter, and more or less attended after that, a sixty percent courseload (once she was four months old, I added a part-time job). Instructors were fine with her being in class, me stepping out with her as needed, and me getting notes from other students as needed. I had previously been in class with moms and babes, and instructors were used to having breastfeeding moms in the first row. I also got a really good pump, and used a study carrel in the library for it. Babelet got in good with the lady who runs the cafeteria, which meant that sometimes I got to go to the bathroom by myself. When I had to do group projects, if I needed accomodation around meeting times or a pumping break, that worked too. Sometimes I miss not having had the full-on new mom experience, but I like how it worked out -- and I think that part of my now 19 month old daughter's happy, sociable personality, and passion for books, comes from being a law school baby!
So, yes, I sympathize with you immensely because of the stress and inflexibility of all this -- nothing's certain, but keep in mind that it CAN work out!! Just try to give up any ideas you have about what being a new mother 'should' look like -- women's experiences are never as universal as we're led to imagine by the media.
One thing I really appreciated about being a student mom was that, while I know women who are full-time moms for six months and then have to return to work full-time away from their kids, even when I was a full-time student my schedule was fairly flexible so I was almost never out of the house 8-10 hours a day. So, I was full-time on paper, but for a year and a half, I got to spend lots of time with my daughter.
Sorry for the ramble -- best of luck to you!