Hello, Yesterday, I was rubbing my 5 year old son s back and then made my way up to the back of his neck.....On the right side of his neck, just above his collarbone, I felt a HARD, pea sized (maybe a little bigger) lump in his neck. He says it doesn t hurt. He has been feeling warm the past few weeks, but has NO signs of the flu. He just had blood work done 2 months ago, and his peditrician said he was as healthy as a horse, as a blood work was all normal. But, this was before I felt the lump. Is it something I should be worried about??