Potentially she might be in labor and have a pup turned wrong or too large to deliver.

Or she might just be doing the nesting they do before going into labor.

If you can feel any rippling in her sides when you lay a hand along her abdomen, if she vomits, or if she pants as if warm without her really being hot those would be labor signs. (The vomit is because the push impacts both directions.)

Dogs are pregnant for about 58-65 days, or about 9 weeks counting from the first mating.

You can read more about pregnancy and whelping in dogs here
http://lowchensaustralia.com/breeding/pregnancy.htm
This site goes over signs your dog is pregnant
http://www.debbiejensen.com/signs_of_pregnant.html
If you need help with financing vet care you might check out Care Credit
http://www.carecredit.com/
A credit card company for health care, including veterinary care.
"With a comprehensive range of plan options, for
treatment or procedure fees from $1 to over $25,000, we offer a plan
and a low monthly payment to fit comfortably into almost every
budget." They have a zero interest program if you pay within a certain time frame and they list the vets who work with their product.
These sites go over the whelping process including pictures and how to tell when something is wrong
http://www.dogbreedinfo.com/whelping.htm

http://www.dogbreedinfo.com/whelpingsecondstage.htm

http://www.worldwideboxer.com/birth.html

Hope this helps you!