So, I'm on lots of e-mail lists for pregnancy-related info and somehow stumbled across the must-have popper stopper. (I'm kidding about the "must have" part.) Apparently, all this does is cover your belly button so it isn't popping out.
In searching for a direct link to the popper stopper though, I found it available from what I thought was a belly dancing website. Not just any belly dancing website though -- a belly dancing maternity website! Turns out it is just a hip/fashionable maternity store:
Related, after I posted this photo, my cousin Lisa asked, "Does your belly button really stick out like that??!!" And that was a month or so ago -- you should see it now.