IF u r confident on ur study then no problem,
i m also doing self study,
i m not joining any class for PE-1,PE-2, & final also .also not for CS executive.
I thinks everyone try own capability at least one time.
i suggest u 2 give one chance to urself.
after that u know ur capability.
joining class is just for guide purpose but when u do self study then u try to uderstand the concept or logic behind the matters.it will improve ur analytical skill & ur confidence.
best of luck.
disclaimer :- this is my own opinion