please help me find a way to break my pregnancy news to...

Andrea
My little brother ! 
I'm 17 weeks pregnant, I get married next Saturday and my mom has asked me to keep the pregnancy from my brother until I at least got married..
Well she wants me to find a creative way to break the news to him.. 
He's my baby brother, he's 9 years old and I feel awful keeping the news from him..
I've searched for creative ways on Pinterest and I haven't found anything :(
Would you ladies help me out ?? 
Any ideas would help :)
P.s- I'm having a gender reveal at the wedding so it would have to be done before then