I'm now 34 weeks, and not having it so easy. I def had to up my water intake, which made a HUGE difference, but I also am retaining so much water that my hand was hurting from the swelling. I am using a wrist guard which helps alot. The pressure is less and I only start to feel contractions when I over exert myself by walking too far (down the hallway!), or pushing myself to work with some of the harder kids.
I just hope I make it to the end of the school year!!
How far along are you? I am a teacher too, and at nearly 36 weeks, am feeling pretty run down. I have been trying to plan my classes so I can get some rests during the day - e.g., staggering tests/quizzes/lectures in different courses for different days so I can have a bit of down time. I'm not sure possible that is as a special ed teacher but you should have an aide or two, right?
I also noticed I have to eat more regularly during pregnancy. I keep trail mix, etc at hand and eat at least a few bites of something every few hours. I've also bumped up my water intake quite a bit and that seems to help with my energy.