one of the lymph nodes on the side of the babys neck is a bit swollen. its about twice the size as the one on the other side of her neck. its only the one that is swollen and it doesnt seem tender or like its hurting her, and she still has a bit of a cough and some congestion left from our cold last week. should i worry about this or is it normal? should i just worry if it starts to bother her or if it stays swollen?