What should I do if the school threatens me with Truancy Court for my 5 years old child who is attending Kindergarten in NJ?

My child is attending Kindergarten at a Public School in NJ. He was absent a couple times due to doctor's appointments to comply with the NJ's requirements for Kindergarten. I sent the doctor's note to the school and was never told that he should come back after the appointments or that those absences will be considered unexcused. He was absent another because he had an allergic reaction in school and his face was swollen ad red. I spoke to the nurse who did not required a doctor's note or advice that the absence will be unexcused. Also, prior to a family trip I called the school and let them know of my intentions to travel for a week. The teacher provided work for him to do while away. He did all the required work and returned to school. I was not informed that these will be considered unexcused absences. Last Friday, I received a letter stating that I will be referral to Truancy Court. He is 5 and the law says that attendance is a requirement for 6-16 years old.