Since I'm a teacher at a really small private school and I love my job I was very open about trying to have a baby right from the beginning. I knew it would be hard to cover my maternity leave and giving a lot of advance notice seemed like the right thing to do. At first that seemed like a huge mistake. My boss very kindly told me that my next year's contract would be withheld unless DH and I agreed to stop trying for 6 more months to avoid a mid-year baby. Obviously I was very very upset and stopping wasn't an option for us - those same 6 months were supposed to be our best shot. I prepared myself to look for a new job and told my boss that I was ready to leave if I had to. I guess I called her bluff because she gave me my contract anyway and said she hoped we got pregnant. I was really angry about this for a long time - and the whole thing was morally reprehensible - but I think that fertile people just really really don't get it and she was trying to act in the best interest of the school. I should note that since that happened she has been very supportive.
So I kept my job and we kept trying.