I've had a cough and chest congestion for three weeks. antibiotics and otc meds aren't helping. what else can i do?

See a doctor: Are you a smoker? Who gave you antibiotics and why aren't you asking them? The overwhelming probability is that this was viral, or an atypical organism like mycoplasma or chlamydia, but making this diagnosis without a history and physical is impossible. Go back and see the person who prescribed antibiotics, or in the alternative see someone else.

See doctor...: Possible etiologies for this cough include bronchospasm from any cause, (like allergy), gerd, post-nasal drip or a combination of factors. All of these have different treatments so you need to see your doctor so the correct diagnosis and treatment can be given. If you are short of breath, go to the er for evaluation. If you smoke, you need to quit today and your doctor can help with this as well.