A Matter of Timing
When should you tell? Professionally speaking, it's better to give your employer as much notice as possible. She'll probably appreciate the early notification and that goodwill may carry over in your negotiations and in your ongoing relationship with the company.
Although the FMLA allows for exceptions ó in the case of early labor or complications, for instance ó under normal circumstances, it requires that you let your employer know your expected last day no later than 30 days in advance. That means you must notify your supervisor by your eighth month (by which time the situation should be screamingly obvious!).
While many women wait until they've completed their first trimester, after which time the risk of miscarriage is reduced, others have a different time frame. One woman informed her boss at two months because she was showing early. Another waited until four and a half months, after she'd received her job evaluation and raise. "I wanted to make sure my salary increase went through," explains editor Carol Killmaster of Chicago.