On the right side of my neck, my lymph node feels swollen/tender to the touch, what exactly could that mean ? should i worry ?

Probably fine: Lymph nodes are immune factories. They swell most often when they gear up to combat a local infection. Insect bites, colds and other respiratory viruses are the most common causes. Yes it can also be something serious but that is very unlikely. A cat scratch can lead to a hugely swollen lymph node. If its getting very big or not shrinking within a week or two, see a doctor but that is unlikely.

Usually inflammatory: Cervical adenopathy or enlarged lymph nodes is usually associated with inflammation/infection, such as sore throat or tonsillitis.Runny nose, sore throat, fever and other indications of an upper respiratory infection. If these do not subside in reasonable time period or symptoms get worse should contact physician.The lymph system important part of the immune system to defend viruses, bacteria, etc.

Lymph Nodes: Swollen lymph nodes can be a sign of many clinical conditions from a simple viral infection to something more serious. I would highly recommend that you see a physician who will determine what tests and or treatment are best for your specific situation. Do not let this go unattended.

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.