Was never an issue for me. If in my opinion the kid was sick enough to take him to the doctor then he was too sick to go to school and someone wasn’t going to work that day.
At least we had the luxury of being able to schedule an actual appointment time for my son. My poor mother had to sit for hours with me or my brother when we went to see the doc. The old horse doctor we saw had a first come first serve policy, it was up to you to keep up with who came in the door after you. Nothing like 20 people hacking, sneezing, babies crying, etc. sitting in the waiting room watching the Price’s is Right on a B&W T.V.
I don’t ever remember my brother or I going in after hours. No one had to miss work during the day, since my Mother was at home, and my Father wouldn’t have missed work to take us to the doctor, if we remained children for the entire life of the universe.