Depending on how soon the examiners mail in their 'stuff'. Your call sign should be on the FCC web site as soon as Wednesday of this week (my nephew's was that soon). It might take until Friday or Saturday though.
Check out here for your new call sign:
Once it's listed, you can transmit, although I'd recommend a printout of the page showing your call sign.
Get your radio soon and get on the air!!! It's a blast.