If you have already an appointment and passed almost every Whizlabs exams then you are ready to take
SCJP. I have passed all Whizlabs exams. After that I have started to review every question again. After SCJP (86%) I have realized that I spent to much time to accomplish this task, so if you had good overall score in Whizlabs
you should go on exam without doubts and fears.
Good luck!