Thanks for your query.Based on the facts that you have posted it appears that you have enlarged lymph
nodes in groin
These nodes are secondary to some infection in a area draining in n these lymph node. Though you do not have any symptoms even a sub clinical infection in draining area can give rise to enlargement of lymph nodes.
Consult qualified surgeon for clinical examination and take some antibiotics for a week and monitor the size of these lymph nodes.