Hi guys, I am 21 years old and  I have extreme health anxiety and just to say I am on medication and treatment for this so I am okay! The only concern I have is I have had swollen lymph nodes for some time now, I had my doctors check them multiple times 10 times plus and even got an ultrasound to make sure, the ultrasound results reassured me for a little while because the radiologist told me himself it was normal, he says that they are all under 1cm and he double checked and took pictures of them to make sure and to send to my GP, he told me he does know that what I am feeling is real but he says it is not of any concern, although he said this, I still have the same lymph nodes that worry me as one or two of them are hard and fixed in place, they feel large to me but there not I'd say they feel about 6-7mm mabye less on the scan he said none exceeded 5mm , they do not pertude from the skin and seemingly can only be felt by me, the two that are hard one is movable but not much and the other is not and feels to be almost on the bone on the back of my neck. Mabye it might not be a lymph node, but the only way I can describe it is like a small round shape ball or dome shaped as it does not go all the way around and is hard and rubbery or smooth. It does not feel soft, and is very small but larger than any of the other lymph nodes I can feel, reading on the internet (I know I shouldn't) it tells me that lymph nodes that are of this nature can be malignant, but every time I raise the concern they say it's not anything to worry about and it's probably just a reactive node or it is just enlarged from a previous illness and will probably just stay that way. I was wondering for my own purposes and self assurance is there any way I can request a biopsy? Because although I am happy they tell me it's normal I am still abit shook. I should also mention that they have done multiple blood tests and assured me that if it was something like cancer especially Hopkins lymphoma or a blood cancer they would see inconsistencies in my blood which they do not, they said my white blood cell count would be very high and mine is actually on the low side. I do have high prolactin levels although this could be anything from stress to benign tumors and I am on a waiting list for an mri but they assured me I am very likely not a case caused by benign tumors as I still get a regular period. Anyways sorry I know I'm writing a thesis here on this but I would really appreciate if someone could tell me if I could request a biopsy or somewhat reassure me that I should trust my doctors and radiologist opinion ! 
thank you guys !