when do I announce?? :)

My hubby and I just found out I'm pregnant a few days ago! So technically I'm 4 weeks and 3 days along now. Wow! 
When do I announce though? How long should I wait? It's kind of driving me insane, especially because my mom came to visit the DAY AFTER I found out!!! I'm still putting myself anonymous in case any of my family or friends happen to be on this app ;) ha.