There are thousands of forums with women discussing all the negative side effects of birth control. Off the top of my head, you can visit http://iud-divas.livejournal.com/, which is women who are considering/have IUDs, and many of them report the negative (often severely so) effects of previous hormonal birth control usage. Otherwise you can visit bedsider.org, which talks about side effects for all birth control methods.

The pill is an incredible win for women's health. Unfortunately, not all women can use it effectively, safely, or comfortably.