IMHO, age is never a valid factor. I was 7 when I convinced my mother to neuter my dog. She wanted to breed him and sell the puppies for money. For what it's worth, I'm only a year older than you. I don't like giving out my age, but I feel that the age factor is a rather limp excuse.

But.. I digress. There are two suggestions that I see being repeated over and over again: 1) at the very least, call your vet 2) spay her ASAP. That is all that we ask of you.

Also, where do you live? If you can give a general location, I'm sure we can help you find lower-priced/affordable veterinary services. It was also mentioned that some vets offer payment plans. Please search every route you possibly can to ensure the health of your pregnant puppy and her puppies as well.

Okay, I promise this is my last thought, but could it be possible that your puppy is having a false pregnancy?