Pregnancy announcements for kids

SeeYouNextTuesday • Single atheist badass career Mom. I say it like it is because I'm too old to play games and I don’t have time for fluff. 😘
I am not big at announcing pregnancies in crazy ways. If you've read my posts before, I'm much more about the baby and the journey together, rather than the cutesy I'm pregnant announcements. 
You know when people are so focused on the engagement, then the engagement party, then the huge "It's my day" wedding (makes me throw up a little in my mouth), that they get married, get depressed, and then within a short period of time divorce. We are missing the point people! It's about the marriage, not the party! My husband proposed to me while cuddled on the couch watching a movie. He had this big thing planned for Christmas, but he couldn't wait to hear me say yes. It was a simple moment, and so indicative of who he is, and that's what we are like. 
Ok, I'm off my soapbox. So, I feel the way about pregnancy announcement. If you've read my prior posts, I told me spouse at 2am when I tested. He knew I was testing sometime early that morning. I woke him and said, "hey, we did it." He answered "awesome, I have super sperm" and went back to bed. Announcement over. We are super excited and can't wait to be parents again. We had similar experiences with our first two boys. 
I do however want to do something for the boys. I'm not sure if we will tell them after the first ultrasound at 8 weeks, or the second at 12. I would like to get them something though to show them they are going to be big brothers. Nothing too crazy. They are almost 4, and 2.5. What do you suggest for the kids?