Painful swollen lymph node near clavicle don't feel sick and other nodes are normal what is it? should i be concerned? just got flu shot related?

Get checked out.: There are some lymph nodes that we're okay with being temporarily enlarged, and some that we're not. Big lymph nodes near the clavicle should be evaluated by your doctor and closely followed. It could be related to the flu-shot, but if it were me, i'd have it checked out.

Monitoring Centers: Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.