Advice

Hi guys, I'm 7 weeks, EDD 8/21 with my first child I was wondering if anyone had advice on how to stay healthy if I work with kids? And when is a good time to tell my boss. I won't work between the end of July - Sept 7ish because the kids don't have school, but I don't think I'll be prepared to return to work in the beginning of Sept. My new appointment will be the end of Jan when I'll be 10 weeks. Is that a good time to say something? Advice please. Thanks