The fact that you're a student has nothing to do with it.
The fact is that there's a backlog of orders.
Why? There were some early models with the Sandy Bridge issue that had to be re-issued, plus all the others who ordered after the recall was announced.
This means there's a backlog of more than a month at Sager. While they're usually pretty fast, what do you expect when there's such a backlog?
Not to trivialise your concern, but 4 weeks isn't that long to wait when you think about the possible backlog.
I see, I just wanted to know the reason why my laptop was being delayed, since when I first ordered they told me I should be able to get it in 21 business days.
I agree that 4 weeks isn't that long now, I can wait for at most a couple of weeks. But not too long since I need to go to poly, that's why I am worried.