Need advice telling employer I’m pregnant as one of the only people with a child already

Hi! I’m 20 weeks with my anatomy scan scheduled for tomorrow. I’m due July 4th, but I wanted to wait until after that appointment to tell my employer. I am remote in a different time zone while most of my team is close to the headquarters. I flew in for the holiday party a month ago and saw most of my team, but wasn’t showing very much.

My boss has no kids & only 1 person on my team has an elementary aged daughter (I have a 6 y/o son) - everyone else is older, so I’ve been super hesitant especially being remote. I’ve been able to attend appointments & accommodate being sick early on just fine.

Do I tell HR first then my boss? It’s giving me so much anxiety because my team doesn’t have small children, so the culture around that feels intimidating. My old employer wasn’t like this!