Would you be upset? MIL drama 🙄

Me and my significant other have only told immediate family just because we want this to be special to us (this is our fourth and last). We made this clear to both our parents. The other night we went out for a birthday dinner, before everyone arrived my mother in law was talking about the baby which is fine. Then when all the other guest arrived she loudly asked to us “so when are you going to tell everyone?” Which then everyone started drilling us about what we had to tell. I’m mad because I feel this was done purposely but my significant other chooses to believe otherwise. Am I over reacting?!