Totally new to this app, and so lost!

Alina • HE>i •Wife •Mother •Expecting #2 •FollowerofChrist •AnimalLover
So I have a few questions. When I post on here, how do I know when someone replies? Does a notification come up? Or do I have to search threw everything again to find my post? Also, I see a few abbreviations. What are the common ones, the ones I should know. I'm assuming TTC stands for Trying To Conceive? And finally, how many people have actually gotten pregnant using this app? 
Thank you!!