I'll Take 1 Straight Jacket Please

Yesterday morning I took Max for his abdominal ultrasound and I left the appointment feeling a little bit crazier then when we went in.
There was a sense of deja view that left me with a knot in my stomach that I just couldn't untie over the course of the day.
Before we knew that Nick was sick he and I made many trips to the doctor and to the emergency room, symptoms were always over looked or explained away without ever thinking that there was anything sinister brewing inside his body. He was tired, thin and not gaining weight because he was athletic and played a lot of hockey, his lymph nodes were swollen because it was cold & flu season, he had stomach and back aches because he was constipated.... nobody ever said hey lets check this kid for cancer.
Yesterday I got the unnerving feeling that this was happening again, last December we discovered that the nodes in Maxwell's stomach were enlarged and since he was a baby hes had a predominant one in his neck as well. Yesterday was his follow up and wouldn't you know the nodes are still bigger then they should be and low and behold despite having daily bouts of diarrhea the ultrasound tech said that he is constipated as well.  My mind began to race..... tired, thin, slow to gain weight, general unwellness, swollen nodes, constipation..... oh gosh that knot in my stomach just got tighter.
I am hesitant though to trust my instincts because I could simply just be a paranoid mom, that is likely the answer. I have asked over the last year if Max should be monitored for lymphoma and was told that while there is a slightly greater instance of the cancer amongst siblings there was no need to check Max.
They have done blood panels and haven't said that anything was out of the normal range.... that's a good sign. They did an MRI last spring and I don't recall them saying that anything looked abnormal but then again, they missed a great big hole in his heart so should I be overly trusting of them???
Really though what is the likely hood that Max would have a Lactase deficiency, an atrial septal defect and lymphoma..... not likely at all.
I feel as though I am already boarding on the brink of no longer being taken seriously, that I am the mom who is crying wolf all the time but then on the other hand I have yet to be wrong with my suspicions.
Maybe cancer makes you overly sensitive to the disease, that's what the doctors say..... I suppose its better to error on the side of caution no matter how foolish I may appear in my request. He already sees a pediatrician, an allergist, two GI specialists, a cardiologist and now I am requesting that he be seen by an oncologist.....
I wonder if straight jackets come in pink?