When to announce pregnancy on social media?

I’m only 4 weeks, and want to wait to announce to social media AT LEAST until after our first ultrasound and appointment when I will be 8 weeks (4weeks from now). Our closest family and friends already know, so we had time to celebrate with them and will have their support no matter what. My SIL said I should wait until 12 weeks so if something happens (💔) I won’t have to explain myself. And MIL wants to announce right now. (She is so excited). This is our second and we are sooo happy, but I want some honest opinions on the subject😬