Got BFP day after accepting new job: obligation?

mlrafiki

Hey all, I accepted a new job on Monday (a senior position), and then Tuesday, I got a very clearly positive HPT.  It put all the symptoms I've been having in context, and today I took a second test, also positive, so I'm 100% certain that I am preggers. Hubby and I plan to do the usual don't-tell-anyone-till-2nd-trimester deal, but I feel a little awkward about my new employer, since obviously he didn't bargain on my being out for maternity leave in 8 months.  While he seems nice and supportive of families and I feel confident I can do a kick-ass job in this role, I'm still a little uncertain as to when and how I should let him know about the pregnancy.

So, what would you do?