Mother in law

So my husband and I found out we were pregnant a couple weeks ago so we ended up telling our parents. We were not going to tell anybody else and told them that we were not announcing it to anybody else for a long time.

Fast forward I go to a family event today of my husbands and his grandma sit down in front of his entire family and says she’s so excited for the baby as my mother-in-law here’s this she quickly tried to get her to stop talking. And I say what because I was so shook and thrown back I was confused and didn’t know what to say and she said we’re so excited for the baby to be here. As my mother-in-law is trying to say that nobody else knows.

So I guess my mother-in-law told my husband‘s grandparents that we were pregnant. When we told her we weren’t going to tell anybody. I haven’t said anything yet I’m trying to cool down. Any advice ???