Advice please😔

We at HER family get together, I don't know half of the people! She goes and introduces me like this " this is my sons wife she's 4 months pregnant with a boy" and I told her not to tell anyone!! eventually the news got out to my sister in law who I'd like to personally tell myself, cause my husband and I haven't decided to announce yet.Like I haven't even told my own family yet! Like WHAT THE FUCK I'm most pissed right now, what do I do!?