If you expect something to happen, you believe that it will happen.

If you are expecting something or someone, you believe that they will be delivered to you or come to you soon, often because this has been arranged earlier.

If you expect something, or expect a person to do something, you believe that it is your right to have that thing, or the person's duty to do it for you.

If you tell someone not to expect something, you mean that the thing is unlikely to happen as they have planned or imagined, and they should not hope that it will.

If you say that a woman is expecting a baby, or that she is expecting, you mean that she is pregnant.

You say 'I expect' to suggest that a statement is probably correct, or a natural consequence of the present situation, although you have no definite knowledge.

You can say 'What can you expect?' or 'What do you expect?' to emphasize that there is nothing surprising about a situation or a person's behaviour, especially if you find this disappointing.