The other thing to remember too, is what would have happened anyway if you didn't find out you were pg until 10 or 12 weeks. Nothing they can do about it, but a resume is meant to highlight your working history, qualifications and your abilities, NOT whether you are pregnant or not. And seriously, would it really matter if it wasn't in writing. They can't sack you just coz you're pg...Just tell them when you get there.