So around a year ago I noticed these small lumps under my jaw. I've noticed there's around three on the right side and maybe around 2-3 on the left side. They are hard and move around freely, they also don't Cause any pain or discomfort.  They haven't changed in shape or size over the year. I've been to my GP three times. And was sent twice to a specialist, who told me they were 5mm bumps that were likey lymph nodes. (He done all this just by feeling my neck and I'm not sure he even felt them as they can only be felt when I'm sat in a certain position, I had to point them out to my GP as she couldn't feel them). It's my understanding a lymph node swells up when there's an infection but I've had no other symptoms whatsoever. I'm scared it's something 

more sinister and don't know what to do!