Baby announcements

Ok ladies I need opinions I have a family size of like 25 and well I wanted to send out announcements that we are having baby #3.. But I am only 5 weeks so I am not sure when to do it.. I haven't told anyone but my best friend who is also pregnant we are due at the same time.. And my husband and kids know and I feel that if the kids see the family they will tell.. What do you all think would you send an announcement or is it too soon????