I am 15 and about a month or two ago I noticed a knot on the right side of my neck towards the back. I went to my doctor and he felt around and decided my lymph nodes were swollen. He basically said it was just an infection and prescribed me Cephalexin (anti-biotic) to be taken every six hours. I have now taken all the antibiotic and my lymph nodes are still swollen. I got on here and discovered that swollen lymph nodes are one of the 15 most commonly ignored symptoms of cancer. I am going back to my doctor ASAP but I am a little freaked out and just want to know if anyone on here knows anything.