When to tell new employer about pregnancy

I knew I was pregnant (6weeks along) at the time of my interview. However, with my last pregnancy when looking for a job I felt that it negatively affected my chances of being hired. I know legally it shouldn’t but it absolutely does.

So this time around I decided I’d wait. I was offered the position I wanted at the hospital. I accepted- now I have a couple of meetings to work out the paperwork and then training starts in a month.

When do I tell my new employer that I’m pregnant? I’m currently 11 weeks along now.