I'm Currently Experiencing Symptoms Which I Think May Be Some

I'm currently experiencing symptoms which I think may be some sort of pneumonia or bronchitis after having had flu-like symptoms for several weeks before. I cough, and feel a lot of pain in my chest, and sometimes when I am coughing particularly a lot some sort of fluid which I initially mistook for vomit, but now think to be mucus - comes out of my mouth. I haven't seen a doctor about this yet and since it is Sunday my doctor won't be open. Does this justify an ER visit?