Actually frozen cycle dun really need to book in advance. After review with Dr, just tell him when you want to start your thaw cycle and he will write a memo liao. But do follow-up with ivf centre to confirm they have seen the memo in your file.I see.. Hope you strike the first time, don't need to go for the frozen cycleI just kiasu a bit, thinking to book in advance for the next if the first failed. Lol!!