ah its a hard one legally they can't NOT give you the job because of you're pregnancy but i don't know any employer that would be willing to give you the job so not telling is the only way i can see you getting the job. Saying that if i was an employer and found out someone hadn't told me i'd be ****ed.

Either way they don't have to keep your role for you as you won't of been with the company for a year so once you leave you leave basically.

My advice would be to go upfront and hope for the best, explain that you're expecting but you really want THIS job and that you plan to return to work quickly after, the thing is what will they do whilst you're away? they can't put someone else on for such a short time so i don't really know if it will work sorry