This morning Lucas had a Dr appointment to look at his neck. After she saw the bump and felt it (it is squishy and moves a bit) she determined that the bump is a big lymph node. Apparently lymph nodes are the "drainers" of bacteria and can sometimes get swollen when it is draining any infection you may have. Recently Luke had a fever and was not feeling well and right now we all have a bit of the sniffles, so that could be the reason it is so swollen.
She measured it and said if it was not gone in a month -or if it looks red or irritated- to come back in. It doesn't seem as Lucas even knows it is there, so hopefully it will be gone very soon and we can stop worrying about it. =)