Mother in exam room during son's physical exam

My son is not quite old enough to be getting too embarrassed about my presence in exam room during his physicals, so I feel it is perfectly appropriate for me to witness the whole thing. I want to make sure he is healthy and developing normally, and I may need to ask some questions as well. All visits included genital check at the end of the exam where the doctor usually pulls his underpants to his knees and conducts hernia and testicular examination. Since there is no shirm in the exam room, this check has been done practically in front of my eyes. As I said above my son is not quite old enough to make a fuss about that. However, I too often see mothers entering the pediatric exam room with older sons who apparently have entered puberty and their son's behavior shows discomfort and embarassement. I am curious to know if the examinations of the boys who are already in puberty is done in the same way as the examination of my pre-pubescent son and what is the age at which mother's presence in the room during the examination of her son is normal.