From what you've said, it honestly sounds like there was NOTHING they could have done about their pregnancy announcement that would've been okay with you. You've found fault with them for waiting until you were home from your honeymoon and had told them a bit about the trip; you've found fault with them for telling your mom before your wedding and asking her to keep it secret out of consideration for you so as not to "steal the thunder" from your wedding; and you've found fault with your mother for "basically lying" to you for a week before your wedding--but of course, if she'd told you the truth, then you'd be mad at them for stealing your thunder before your wedding!
This level of craving attention and thinking that everything should be "about you" for a certain number of weeks before and after your wedding or other major life event is not normal or healthy. I hope you don't take that as me trying to shame you for it--I'm trying, perhaps clumsily, to suggest that if things like that continue to bother you, then you probably need therapy, and you'd be much happier in general after working with a good therapist on this stuff. You would have much greater generosity of spirit--for instance, if a sibling told you they were pregnant even AT your wedding, perhaps you could honestly feel like, "Oh wow, now there are TWO things to be happy about!" And generosity of spirit is its own reward; it feels a lot better than pettiness does.