Way too early pregnancy reveal

Anyways, about a week ago, my mother, who was in Hawaii on vacation visiting my sister, texts and tells me she slipped up and told my sister about it! She did it so casually like it wasn't a big deal. She gave the reason that she is "just so excited" which just irritated me more because, well, SO AM I! In any case, it turns out she told my grandfather too. Not cool! I doubt my grandfather really cares too much (he is a rather far gone alcoholic and has never had much interest in us), but my sister really does. I'm just upset that she took that moment away from me. We texted back and forth and it basically ended with me saying, "I'm not going to say it's ok. It happened and I'll deal, but I'm pretty upset. Just enjoy your vacation for now and we will talk sometime soon." It ended that way because we were in a circle of her saying sorry and me just expressing that I was really upset. It doesn't help that my sister is probably the most likely person to blab to someone else. Thankfully with the distance she probably won't have too many chances. 

So, my mom got back from vaca a few days ago. I haven't texted her, cuz (and this may be petty but) I feel like she should initiate contact at this point. She was in the wrong. But she hasn't contacted me either. It's making me uncomfortable. 

Am I over-reacting and should I contact her, or am I right? Part of me wants to say it's no big deal and just text her like normal, but on the other hand  it is kind of a big deal. I can't ever have that moment now, and I fee like she doesn't fully understand how she was selfish and wrong for doing that. Plus now if something happens (God forbid!) I will have to call and tell my sister. Idk. I just feel weird not talking to her, but I'm also a little stubborn and I don't know what I would say anyways.