I have been sick for about 10 days now. i have a small lump under my chin. could it be a lymph node or something else?

Most likely node: There are several nodes between the chin and a bone called the hyoid. These drain the lower central face, lips, and front part of the mouth. It may also be a dermoid, a skin cyst. If the node sits on or below the hyoid then it could be a node or thyroglossal duct cyst. If it persists past the time the illness resolves then get ENT opinion.

Monitoring Centers: Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells/digested food. Lymph nodes "taste" the lymph everywhere for bad stuff 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.