What Causes Leg Pain In Children?

Question: my son is 3 years old and has pain in his left leg. its been going on for a year. he only cries at night and it wakes him up out of his sleep. The pain is on his shin. The x ray only noted some density along the tibia and femur they thought may have been lead posining (but we have never lived in an old home or been around old paint). He is 100% fine during the day, never complains. He does get some random fevers every now and then but never over 99.4 or so and it goes away on its on. We then took him for blood work, his ESR is 40 (normal range was 0-20) his CRP was 1.8 )normal between (0-1.0). He also showed low uric acid. Monocytes were at 8.2 (normal ranger 0-4.0), neut % 55 baso # 0.04 . HCT 32.6 MCV 72.8 (the HCT and MCV showed flags for low, while the mono, neut, baso all showed high). He hasn't been sick when I took him in for the blood work. We are stumped to know what is wrong. My doctor was supposed to call me weds with results and I have no heard, I only saw these results on the computer program where they download our info. I am just looking for a few ideas as to what could be wrong. I am worried sick about him and can't get to our doctor until Tuesday. Please offer any ideas you could have.

Based on the blood work and the high esr and crb does it seem like an inflammatory auto immune issue? Does the blood work I attached seem concerning or just typical of some small infection? Is leukemia a concern orv would that present as a high overall wbc ?