Can feel my babies nodes on his neck

Hi ladies, last night i took my son to emergency as he had what i felt a lump on his neck. He is 3 months old currently and the doctor said it was a lymph node and nothing to be worried about as it was moving and soft instead of hard which is a good thing.

He told me to keep an eye on it however i am terrified and would like an ultrasound to make sure it is nothing serious like cancer god forbid.

Do any of your babies have nodes you can feel on their necks or is it just me :( im so upset ive been crying all night. Going to see my family doctor for a second opinion this week.