Good you have come back to update. Obviously you will do what you feel is best but this is not the advice of UK doctors.
His advice does contradict the prescribing regime with the actual product. That says 12 days. My consultant is happy with 10 days.
The fact you are being advised to have a week's break to give a bleed doesn't really make sense. It's when progesterone falls in your blood levels that a bleed begins.
The bleed is also dependent on the amount of estrogen used during each cycle. So for example, someone using 1 pump of estrogen gel every day would most likely have less blood loss than someone using a higher dose ( 2 or 3 pumps daily.) A higher dose patch would have the same outcome.
So, you are less likely to bleed much if you miss a week.
If Utrogestan works properly, all the lining should come away after 12 days.
Usually, doctors only suggest increasing the amount of progesterone above the guidance from the manufacturer IF there IS mid cycle spotting, not to prevent it.
However, you must do what you feel is right for you.