Shove your hand down there and feel around for the 'product'.
Seriously, even if it's clogged right now, leave the house and go buy a plunger. Get it at a hardware store if you don't want the girl at Wal-Mart to give you funny looks when that's all you're buying.
Also, here's a trick a plumber taught me that really works: plunge while you're flushing. The pressure from the plunger and water together will unclog it everytime.
I'm suddenly in the mood to go take a crap.