Levonorgestrel
"Switched from BCPs because of terrible side effects. It's been 6 weeks, and so far I've experienced a good amount of pain, bloating, headaches and possible weight gain. I've noticed my body chemistry change in other ways, too. My second period came only 2.5 weeks after the first ended. First was 9 days long, too. Doctor has advised to tough it out at least 6 months. Trying to resolve coverage with insurance co. Law Center for Women a great resource."