What should I do if I don't have insurance & have really bad side pains?

I live in Philadelphia and I do not have health insurance. I feel like something serious might happen soon if I don't get looked at, but I don't have the money. Is there anyplace that anyone knows of where I can go get an x-ray without having to pay too much? I know of free clinics around here but I don't think that's what I should do.. any suggestions please let me know!