Is it normal to have a swollen lymph node on the groin area for over 6 months the lymph node is not to big according to my doctor?

This is a common: Site for lymph nodes to be noted, and can persist over time.

Sometimes: If there is a rash or some other infection in the area that is active, the node can stay swollen. Also some lymph nodes can scar after enlargement and stay big enough to feel indefinitely. The worrisome kind are hand, continue to enlarge, are immobile or fixed to surrounding tissue. Also concerning if other lymph nodes in body are staying swollen. May need to be biopsied or removed if changing.

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.