Help with message/comment notifications on feed..

pinkytoes33

So when someone posts a comment on my news feed, I only sometimes get a notification on my phone or an email that someone wrote something. Even then, when I go into the app, it doesn't show me the new comments. If I go to my newsfeed, I can find it.. But in general, it's hard to tell when someone posts something new to my profile. Am I doing something wrong?