Fight over telling his family

Yulia
I'm so upset with my husband over trying to tell extended family! Anybody else been there?
I'm 9 weeks pregnant with my first and my DH agreed to tell just our parents and 2 close friends who had a baby recently for support. 
His mom has been pressuring him to tell his grand parents when he's visiting them this weekend (we live in another state). 
We agreed not to because he has many uncles and aunts and we are not ready to share And the gramps will likely spill the beans. 
Last night he asked if we can tell them, because he will be able to tell them in person and 'it makes sense' to do it now because he's there and will make them happy. His response to my worries about m/c before 12 weeks and having to break his gramps heart with these news? 'It can happen any time in the pregnancy'
I feel bad telling him no but I'm upset he's asking to do something we agreed against. Anybody else having family pressure to tell to more people than planned?