What can I do to get medical treatment?

Uninsured, Broke, and Jobless. I have been looking actively for a job for 6months. I now have no money, no insurance, and if it weren't for family I would be homeless right now. For the last 4 days I have been feeling pain in the left side of my chest, general dis-ease, and sometimes an odd feeling in my arm. I am concerned it may be a heart attack brewing, but I have no money to seek treatment. I'm at my wits end at this point. No one I know has the money to foot the bill, and especially if it turns out to be nothing. My question is, what should I do? I have no car, no phone, and my sibling I am staying with is out of state till Tuesday. I don't want to go to an ER because of the extra high costs, but I fear I would get denied treatment elsewhere because of my money-less status.