Taking birth control pills for almost 2 yrs after a 7.5 cm cyst was removed. never miss a pill. still get painful cysts every month. why is this?

It depends what pill: U are taking i would rec u take the pill continuously because that should suppress any ovarian cyst formation, if you are on a 21-7 pill and take the 7 pills at the end and have a period those 7 days are enough to permit a cyst to form if you are not going to take the pill continuously then you should be on a pill like loloestrin where u are only off the pill for 2 days so a cyst shouldn't form.