What do you suggest if my little boy (3) has had a swollen lymph nodes in groin and neck for months but bloods all normal?

2 options: If he is seemingly healthy, active, appetite good and no other symptoms, I would recommend watchful waiting. If any concurrent symptoms, he just isn't himself, poor growth or weight loss, fevers, then I would suggest a biopsy of one of the nodes. Make sure he has also had a TB test done as well. Also, if you have a cat, have him checked for cat-scratch disease (blood test).