When to tell your boss you're pregnant?

Diana
Hi, it's my first pregnancy and I probably won't show for another couple weeks, but I'm thinking about telling my boss now that I'm 14w1. I don't want to keep hiding my pregnancy and afraid they'd find out some other way, so I want to just be upfront and control the narrative. On the other hand, it's an early stage startup and I'm not sure how they'll take the news. I'm the first woman to be pregnant so I'll be testing our work policies (nothing explicit about maternity care in our benefits package). Thoughts on whether I should tell or wait?