Different doctors have different fixed clinic days e.g. Dr A has clinic every Mon and Wed AM, Dr B has clinic every Mon and Tue PM. If you stick to the same day/time for follow-up all the time, higher chances that you’ll be seeing the same doctor again. However, this is not guaranteed for delivery of your baby which is dependent on EDD and whoever’s on-call that day. If you like the doctor you’re currently seeing and would like him/her to be the one delivering your bb, best to confirm their availability around your EDD period and if they tell you they’re available then consider switching to private to “book” them as your delivering doctor. P.S.: very common for doctors to go on conference/training leaves during Christmas to CNY period.