Lumps on 20 month old's neck (behind ear)?

My son, 20 months old, has had a lump on his neck (behind the ear about a inch) for a couple months now. He's not in daycare and, expept for a recent cold, hasn't been sick really at all this year. I took him to the Ped a little over a month ago and she said to keep an eye on it, if it got any bigger to bring him back in to have it looked at again. Well, after checking it once a week it didn't seem to change much. Last week, I must have forgotten to check it b/c I checked it the other day and it's twice the size it used to be. Now it seems to be more swollen and stationary (before it moved back and forth fairly easily). He also didn't seem to mind me touching it before, but now he moves his head whenever I try to check it to keep my hand away. I'm really concerned. He's been acting a little off for a while, but he recently came down with a cold (first of the season) so I thought maybe that was the problem. Last night he woke up a little out of it and coughing a little bit. He ended up sleeping on my husband's chest all night b/c he was so upset when he woke up. Never seen him like that. Then this morning, after his morning milk, he threw up. Out of nowhere, and not much. Perhaps a couple ounces. I don't know if he gagged himself with his pacifier or if he literally just got sick and then was fine. This isn't the first time it's happened. It usually happens when I notice an increase in drooling and him putting his fingers/hands in his mouth (which I always attribute to teething). He's gagged himself before by accident. Anyway, he was off today, just not himself. Didn't really want to eat dinner tonight, but managed to drink at least 24 ounces of fluid today. Most of which was milk and he was playing as well. Tonight, before bed I checked his lump again and now it seems like there are two. One directly behind the ear and one about an inch back. The one directly behind the ear is new. I'm really freaking out. Everytime I Google I keep getting things about cancer. Has anyone else had this happen or is there anyone that has medical knowledge that can help me? He has been covering his ear so, I was thinking possible ear infection? I'm calling the Ped for an appointment first thing tomorrow. Any help or ideas, kinds words, wisdom, whatever would be so greatly appareciated. Sorry for the lengthy description. I get wordy when I'm scared.