When to tell the boss that your pregnant?

So I've been TTC for awhile, and randomly got a promotion at work and the 3d day of my new job I found out I was pregnant (woohoo😁). so now I'm 8 weeks (still in my 90 days at work but I've worked for the same place for over 2 years) and I'm dreading the fact I need to tell my new boss. I'm at the point where I can't hide it anymore, thanks to my "all day sickness" I'm in and out of the bathroom 6+ times a day. Im terrified of what she's going to say and it doesn't help that  I'm the only person that does my job. Advice ? When did you tell your boss?