Welcome to TCS....even though it sounds like your girl has been an indoor/outdoor cat...please have her checked by a vet and if she is pregnant, keep her indoors only until she weans her kittens and has been spayed (you also need to keep the kittens indoors only until they have all been spayed/neutered). Cats can go back into heat and become pregnant again shortly after giving birth. Here is a list of low cost spay clinics in Oregon.
Pet Over Population Prevention Advocates Inc (POPPA)
PO Box 5721
Beaverton, OR 97006
This service helps by giving information about low cost programs for s/n of dogs, cats, rabbits, and ferrets statewide. Also, POPPA operates Oregon Neutermobile, a van that visits communities around the state to provide low cost s/n.
Feral Cat Coalition of Oregon
Spay/neuter and vaccinations for ferals, at clinic or at mobile clinic that travels around the state.
Humane Society of the Willamette Valley
PO Box 13005
Salem, OR 97309
503-585-5900 ext 308
Spay and Neuter Humane Association
333 West Marine Drive
Astoria, OR 97103
7741 Cook Underwood Road
Serves the mid-Columbian area in Oregon and Washington state. PROD will pay a percentage of spay/neuter costs, depending on income level, at any vet in the mid-Columbian area, including towns such as Hood River, The Dalles, and Cascade Locks, Oregon -- and Bingen/White Salmon, Stevenson, and Underwood, Washington.
Pet OverPopulation Prevention
PO Box 442
Pasco, WA 99301
Each month, gives out a limited number of certificates for very low cost s/n at participating veterinarians. Call the message center for instructions.
City of Eugene
Low Cost Spay and Neuter Clinic
3970 West 1st Avenue
The clinic is operated separately from the County Animal Regulation Shelter although they are located in the same building.
Pet Population Control & Well-Being Society
800-944-0192 toll free
Rogue Valley area of Oregon
Heartland Humane Society
5311 SW Airport Place
Corvallis, OR 97333
Low cost spay/neuter for pets of people with low income.
Coos County Animal Control
600 Southport Road
Coos Bay, OR 97420
Free spay/neuter for pets, in exchange for the human volunteering some time