I would wait as long as possible before telling.

I'm also a fed and told my boss at around 3.5 months. I was also worried about a negative reaction because my office is constantly short staffed, but everyone was supportive. I know they were not happy to have me out for 3 months but it is what it is and they were happy about the baby. Hopefully, you will be pleasantly surprised like I was. I decided to give a lot of notice so that we'd have plenty of time to work out coverage for my account and no one would feel like I blindsided them or left them in a lurch. I busted my buns that last month as well to get a ton of stuff done and have everything set up for someone else to take over!

Not sure about the FMLA, but definitely talk to your HR. I ended up doing annual, sick and comp time to cover three months so I didn't really do anything special but I was told that if I had wanted to use FMLA I would have had to fill out paperwork for it and get approval since you are going on leave without pay. Also check on any guidance on how much of each type of leave you can use. Other fed friends of mine had told me that they had used 12 weeks of sick leave but I was told by my HR that I could only use 6 weeks of sick leave unless I had a doctors note or had a C-section (which would have given me 8 weeks). I was under the impression that each agency had discretion on that so perhaps you can use more sick leave depending on where you work. Good luck and hope it all turns out well for you!

Hi - I think i told my boss around 15 weeks the first time. It was Jan though so it was a little easier to conceal that time of year. Two suggestions-

Definitely tell your boss before anyone figures it or starts guessing. Take ownership of the situation.

I think it is important to be upbeat, positive, and happy when you tell your boss. Yes, it will cause some disruption for your work team but it is temporary, and this is a very positive development in your life. I think if you act apologetic, sorry, etc, you will be setting a tone that will allow people to behave a certain way towards you. Be happy and and positive, while acknowledging that you will need to work hard to get everything squared away before you leave and that you will come back ready to work.

Actually, OPM has issued guidance that says that the 12 weeks provided by FMLA are in addition to any sick or annual leave you have.
http://www.opm.gov/oca/leave/html/fmlachng.pdf (scroll to the part about "stacking" leave)

A lot of people choose to use their sick/annual during FMLA so that they get paid, but you do not have to (my supervisor, for example, is allowing me to take 6 weeks sick and the remainder of my maternity leave without pay so that I can preserve my annual leave to use for when my child gets sick and to travel to see our families during the 2012 holidays). Based on what OPM says, it seems you could use the 6 weeks sick leave to which you are entitled for vaginal birth and then 12 weeks FMLA leave on top of that for a minimum of 18 weeks maternity leave (if you have the sick leave accrued).

The only caveat is that, to the extent you intend to "stack" with annual leave, your supervisor has the discretion to deny your request for annual leave, so if you have an unsympathetic supervisor your ability to stack would be limited to sick leave during the period of post-birth incapacitation.

I couldn't have waited till 18 weeks as it is pretty apparent I am pregnant. But waiting as long as you can isn't a bad idea. I talked to a few other women I knew I could trust who dealt with being pregnant in our office before I told my boss. But they have to be people you trust not to spread your news before you do. How you do it is your decision. They can't do anything to you. Try a business like fashion where you are putting them on notice for office efficiency. Our office allows 6 weeks sick leave for vaginal delivery, 8 weeks for c section. Then as much annual leave as we have up to 5 months or LWOP up to a certain amount...I can't remember how much at the moment.

I think it is totally understandable to let your team know at 18-19 weeks -- this would be after the amnio, if you get one. I told most people at 10-12 weeks, but really held my breath until my tests (nucchal fold and amnio) came back clear. Not sure what I would have done if they didn't, but I think most people would understand you not wanting to tell anyone until you get the results from those tests. So, even if you forego those tests, 18-19 weeks is a reasonable tell-all period.

By the way, I also used to be an indispensable member of a super important project when I was pregnant with my first, but came to learn that the world went on perfectly fine without me while I took 6 1/2 months of maternity leave. In fact, I did not think of work at all the first few months of leave, and the office was happy to adjust around me once they found a solution. So, don't worry too much!

Good luck!

I wouldn't tell anyone at work before you pass 12 weeks.

FMLA just gives you the right to 12 weeks (not necessarily paid). Whatever leave you have can't be added on to extend that time. Having said that, many agencies will let you take a lot more time off than that (paid or unpaid)--depends on your agency and supervisor. I took 6 months (combo of paid and unpaid).

is it your first? If so its usually harder. The second one you can play down

Take a deep breath and tell them. How they manage their reaction to this news is their problem. What aspects of your boss/work environment are worrying you?

Popular times to announce are end of first trimester, after pre-natal testing, when you are obviously showing.

I suggest emailing the news to assorted HR and safety people (if it is relevant) just so you have it documented.

I'm a federal government employee and an on a team with only one other woman and one team member with kids. I can already anticipate my boss and team not being particularly enthusiastic about my pregnancy (though I'm hoping to be pleasantly surprised). Any tips or advise on when to tell my boss and how to tell my boss?
Also, can feds the full FMLA 12 weeks + accrued sick/vacation time, or are we limited to a max of 12 weeks?
Thanks!