On every post there is a listing of that post’s rewards on the right hand side. If you see “Initial Payout Pending” that means the post has not earned rewards yet, or that it has not been posted to a niche and is therefore not eligible for rewards.
On mobile scroll down, you'll see it just above the comments area.
Don’t see any rewards yet? It may have been posted after the last month distribution. And as long as it is not rated as low quality, your post can still be earning as the platform continues to grow and get more readers.