My Child Is Complaint Of Underarm Pain For The Past

My child is complaint of underarm pain for the past five days. He was seen by GI specialist who diagnosed him functional abdomen 4 months ago. Then the frequent urination started two weeks ago. So multiple pains. He had urinalysis to r/o infection and full work up by urologist including bladder scan which was normal. He had not seen a kidney doctor or therapist yet. Currently awaiting Lyme titter results. Recently treated with z pack for broncitis. What do you think