This website lists the medicaid offices for all the states:
http://www.Cms.Hhs.Gov/medicaid/allstateco
ntacts.Asp
for fast help, you could try the closest planned parenthood office, as they do many annual exams and gynecological evaluations. If you have no funds, they might do it for free or dirt cheap.
If you truly are in philadelphia, I found this place through a google search:
temple university health sciences center - service departments,
family planning
3401 north broad street, philadelphia, pa 19140
(215) 707-3232
it apparently is run through temple university medical school and is staffed by resident physicians with supervision from licenced ob/gyn physicians. From what I could find, most of the 10,000 visits each year is by women who have no money, and thus get the visits and care for free.