I've been in the process of looking for work over the past 6 weeks. If my former boss doesn't sabotage me in the reference process I think I will be offered a position. However, I just found out a few weeks ago that I'm pregnant. I'm still early in my first trimester. Do I tell HR if/ when they offer me the position? This is a part time position so when I do go on leave they'll only need coverage for about 12-16 hours a week. If I don't tell HR when is a good time to talk to my potential new boss about it?