Congrats on your new addition.
Are you saying you want to go off birth control already but don't want people to know? Why would you have to tell anyone that? Except for your OH, that's no ones business. If the two of you have decided you're ready for another one 3-4 months after your little girl, who's to say you can't go off birth control?
If you're worried about people seeing where it's removed from, cold weather is coming soon and you'll be wearing longer sleeves anyway so that should help but I really don't see why anyone needs to know or would even be inclined to ask about something so personal anyway.
Good luck