what happened to the notifications section?

It's available from your profile page.

Weren't you notified

You can still get to it, but some recent update made it seem to disappear. The way to get to your notifications now is to click on your username in the shaded blue area directly beneath the "+Ask" button in the upper-right-hand corner of your screen. That will open a new screen that will show a "Notifications" link in the upper-left-hand corner.

it's hiding out from you