I found telling work was one of the best things I could have done. I had a few appts without them knowing and then I just decided to bite the bullet and tell them. I had only been there 3 months on a 6 month contract. They're were great about it and ended up offering me a permanant full time job shortly after.
I found that I needed quite a bit of time off during and leading up to my first cycle, but it has been much easier in subsequent cycles. I have also been very lucky that it has been kept confidential and no one talks about it unless I bring it up first.