It is possible, but generally uncommon. Most dogs give birth to all pups within 24 hours.
It is unlikely the pup will survie the longer it stays inside her. As Dinkar Singh said, there is an injection which will cause her to go back into labour to give birth; however if she doesn't have a pup iside her, I fear it won't be good for her.
Also, the pup may be too big to fit through the birth canal, which means she would require surgery to get it out.
I suggest you take her to a vet with an x-ray as soon as possible.