I'm sure this topic has come up before...

This is my 1st pregnancy. I'm 9w4d and we told close friends and immediate family on Christmas. Tonight we went out for dinner with my mother in law and she told us she's been telling everyone! After we specifically told her not to because its still too early. I haven't even had my 1st ultrasound yet! I really let her have it... I don't know what to do... I feel robbed. This is special between my husband and myself and we wanted to be the one telling everyone, not her. And the worst part is, she doesn't see what she did wrong. I was so mad I was shaking. Has anyone esle gone through this???