Advice on My 2 year old Son

I’m not sure if this is the right place to find some advice but I hope it is,
I’m from the UK & I am finding it very difficult to find anyone who is or has been in my position as Lymphoma in children is rare.
My two year old son has had enlarged lymph nodes for about nine months, it was first noticed with two in his neck but since then this has multiplied to more in his neck and also two in the groin.
I wasn’t really concerned at first, I was hoping the doctors were going to say it was fairly normal for them to have swollen lymph nodes. But as they have multiplied and his face is pale and in areas blue & purple my concerns are increasingly growing, his blood tests came back normal but this did not satisfy me it doesn’t feel right.
I’ve done some of my own research, I want to know if my research is right & if his symptoms are significant and how other people or their children were diagnosed with lymphoma.
Through my research I personally believe Harley has a low stage Non Hodgkins Lymphoma. Im frustrated because NHL is significantly rarer & he is still playing with his toys doctors will not do a biopsy. From my research NHL often shows NO symptoms apart from the lymph nodes being persistently enlarged, but obviously there are cases of other symptoms such as high unexplained fevers, which Harley has – he has had two in the last month with temperatures to 39.4 degrees Celsius and sickness but no obvious cause, Harley has no infection he has been tested for all the common ones including urine and he has had none and infact had no infections for about 6 or so months so these fevers are completely random and with no obvious cause. Rare to the doctors shouldn’t mean not testing for it because it will always be someones child..

Harley has had a chest x-ray and his spleen checked. These came back normal, but through my research I have also discovered these things aren’t always affected, it is less likely in NHL for these to be effected, and if they are it would be a higher stage lymphoma e.g. stage 3/4 +

Harley has had blood tests, but I have also discovered blood tests should only be used if the child has been diagnosed as the bloods will be tested in a different way to try and identify a stage rather than a diagnosis, it is extremely unlikely they lymphoma would be found in a blood test.

Harleys enlarged lymph nodes are not massive, I have to point out the lumps - but they are enlarged, have multiplied & spread and in one side of his neck they have noticeably got bigger. The doctor was the one to find them enlarged in the groin, and find the others in his neck.

Basically, I have a series of hospital and pedeatric appointments this month, my concerns are high and the doctors aren’t, I believe the risk benefit of a biopsy is worth it and they do not. Untill Harley is awfully ill they will not do anything, his fevers are increasing and so are the lymph nodes – am I right to worry? And what do I do to get the doctors to agree with me without Harley getting worse.

P.S I am aware and obviously hope it is something else as I keep being told this could be something else, but I am not being reassured as to what ‘else’ it could be. My nan also has lymphoma, I know they say there is not proof that it Is hereditary but there are often cases of two family members having lymphoma at the same time.