Rachelle...welcome. A good starting place is this post:http://www.thecatsite.com/forums/showthread.php?t=46743
Also, please remember to keep her indoors through her pregnancy and until she has weaned her babies and has been spayed. If you need a low cost clinic for when the time is right..here is a list:
C-SNIP (Community Spay/Neuter Initiative Partnership)
Serves Kent County and adjacent counties
Grand Rapids MI
Low cost mobile clinic for pets of people with low income.
West Michigan SPCA
Silver Lake Animal Rescue League
248-545-6583, extension 5 This organization has a program for spay/neuter of pets of low income people in metropolitan Detroit.
Long Lake Animal Hospital
5044 John R Road
Troy, MI 48098
Humane Society of Huron Valley
Ann Arbor, MI
Kalamazoo Humane Society
4239 South Westnedge
Provides some assistance for the spay/neuter of pets of qualifed low income people.
Animal's Best Friend
PO Box 443
Oshtemo, MI 49077
For pets living in Kalamazoo and Van Buren counties, ABF provides small subsidies at particular veterinary clinics each month. Call for details.
PO Bx 130944
Ann Arbor MI 48113
For feral cats in Washtenaw County