Starting a new job while pregnant.

I am 6 months pregnant. I start a new job Monday. So nervous. I did not inform them

I was pregnant. When I went to my interview I was already fully showing and I was 5 months pregnant and was offered the job the next day. But never touched On the subject that I was expecting. Has any of you ever started a new job while pregnant and not inform your new employer until you started? I know they cannot discriminate for pregnancy but Still a little nervous to start. Has anyone had a similar scenario ?