When should I tell my boss?

Br

So I found out I'm pregnant today. Yay! ♡ I also am in the process of switching to my dream job. I'll start in 2 weeks. I didn't know I was preggers during the interview and probably wouldn't have brought it up anyways. Now I'm nervous because it's not a normal job where I can play it off for a couple months after training and getting to know everyone. I work in a vet clinic and have to take radiographs, monitor anesthesia, and play in cat litter all day. Anyways, I don't want my co-workers and new boss to be annoyed and think I was hiding it... Has anyone been in a similar situation or advice?