I know how nerve wracking having your pup swallow an object is...I lost many a sock to Ernie. Hopefully if it is just a small one it will pass on its own. Is your vet on call? Maybe you could call them just to get their opinion.
We saw the paperclip about the same time and he grabbed it up before I could and ignored the "drop it".....I tried to dig it out of his mouth but he got that stubborn look on his face he gets sometimes and then it was too late...
My vet is a very small office - I think I can call and leave a message and someone would call me back.
If you could see some of the things that passed through our Shadow, you wouldn't worry about a paperclip! She got into my crafts bag when she was about 8 months old, and ate a number of things - buttons, candles, thread ... the scary part was when she passed the wick from a pink candle. I thought it was a worm!