Legal to start a new teaching job while being pregnant?

I'm a teacher but currently unemployed and looking for work, and currently 3 months pregnant. When the school year starts, I will be 5 months pregnant. I will need to take maternity leave in January/February. I really need a job, but I am afraid to tell the employer during the interview that I am expecting. I'm not showing now, so I can get away with it. But when school starts, I will be showing so I know they will know the obvious by that point and will probably be rather surprised when the new teacher shows up knocked up on the first day of school. Is it legal for me to not tell my employer that I'm pregnant until the school year starts? I'm afraid if I do, then they will not hire me. On the applications, it asks if they need to make any accommodations for me, do I need to specify maternity leave on there? Thank you