Bumps on back of head and neck

My LO is 11 weeks old and as early as 6 weeks old I have been able to feel small moveable bumps on the back of his head by his ear and on his neck. At his 2 month appointment they were checked out and they were not concerned and said it was the development of his lymph nodes but to keep an eye on them for any change. There hasn’t been any change and they are smaller than a pea and moveable, he doesn’t have any symptoms of illness, and it seems like he doesn’t even notice them at all only me. I don’t like that they are there but it doesn’t seem to worry the doctors. Has anyone else experienced this with their LO and did they go away?