When to announce (when the beans have been spilled)

We are 7 weeks pregnant with out first after struggling to conceive. We told our parents right away while making sure they knew it was not to be announced. Our family is huge and decently close. My dear mother has apparently told several family friends and now some aunts/uncles. When I asked her why she was telling people when I asked her not to, she said "well, shelby you can't expect me not to tell people". My brother and SIL are also expecting and announced at 4 weeks. We just were more comfortable with waiting.

So now...the question is do we go ahead and announce next week (8weeks) after our Ultrasound so we can at least share it while it is still OUR news and mom hasn't told everyone and their dog.

OR.

do we wait till 12 weeks, understanding that many people will already know since news travels fast in our family apparently.