Not sure what to do.!!!!

I lost my job a few months back. We just found out that I am about 7 weeks pregnant. I was looking for a new job and I really want this job so bad. However I Just found out that they want to offer me the position and I am just scared because now I'm pregnant and I don't know how to tell a new job that I'm pregnant. My job requires standing a lot it's at a bank so I feel as if I need to mention it incase I just need a break during the day especially if my morning sickness kicks in. How do I go about this? I mean by law could they be upset I didn't tell them? I went in for the interview before I knew. I'm just worried.