DeAnna, sometimes where we feel pain is not where it starts. I agree with PJ that this does not sound like a breast cancer symptom. In addition to a pulled muscle, your symptoms sound like they might be respiratory symptoms. If you are coughing and sneezing more than usual, check your temperature and contact a doctor if you are running a fever.
Most communities have options other than the emergency room for non-emergency medical care. In my city many drugstores now have a walk-in clinic for routine medical care. Urgent care clinics are another option. These range from extra hours offered by a doctor's office to stand-alone clinics. If the problem did turn out to be more than they could treat, they would refer you to a more appropriate place. I asked at my doctor's office the other day about what they charge uninsured patients, and they told me that an office visit costs $65 to $125 dollars. That's a lot of money if it turns out you just have a cold, but it is not much if you need treatment to prevent a small problem from turning into a big one. Also learn about free clinic options available in your community. Almost every city has free or low cost clinics run by the county or by volunteer doctors.
If this pain is a pulled muscle or a chest cold, it will probably get better on its own within a couple of weeks. But find out now what medical services are available for uninsured people in your community so that you have an option other than the emergency room for your medical care the next time you have a problem. I hope you feel better soon.
It sounds like you may have a pulled muscle, since it's responding to all sorts of physical prompts (sneeze, raised voice, etc.) Or you may have a cyst, which can be quite painful. Thankfully, pain is seldom a breast cancer symptom. If your breast starts to appear infected (red, hot, swollen, itchy); or if you discover a lump, or notice some other physical change in appearance, then you should see a doctor. Also, you should see a doctor if this pain lasts longer than a month, without getting any better. Ask your hospital if they have a lower-cost walk-in clinic, or a long-term payment plan; or how they handle patients without insurance. Don't let lack of insurance stop you from being responsible about your health, OK? Take care- PJH