surprise: you thought you quit, but you got fired.
generally, at-will employees can be fired anytime and for any reason. so, assuming you were at-will, your boss could decide to let you go NOW when you expressed a desire to go 2 weeks from now.
unless the 2 weeks' notice was required (i.e., by company policy), you were not legally required to give the notice, and your employer is probably not required to pay you for the 2 weeks. BUT, because you were told not to come back, you have been involuntarily discharged and you are now probably ENTITLED to collect unemployment.
if you'd resigned, you probably couldn't collect unemployment. but, since you were involuntarily terminated (i.e., told to leave "today"), you now probably have the right to benefits.
