Good way to announce on halloween ?

I'll be 14 weeks by then and have an ultrasound . we were thinking of announcing until Christmas but we changed our minds and plan to announce by halloween. I found this picture on google and love it , I will be including a sign that says  " were adding a pumpkin to our patch " with a picture of our ultrasound and  we will be taking a picture and sending it to my husbands parents house do you ladies think that's a good idea or no ? I told my husband about it and he made a face (as a I don't like that idea face ) . Anyone else plan or have announced at halloween ? If yes may I see pictures to get more ideas