I also teach kindergarten all day and I'm almost 39 weeks, still working til Thursday! I have a pair of slippers at work that I often wear most of the day. My feet are so swollen and get very sore as well. I try to sit as much as I can, with chairs set up around the room. I also wear Sketchers go walk 3 sneakers and they are like walking on clouds. The only problem is they are tight on my swollen feet! I hope it gets better for you, good luck!