I just started taking a version of Seasonale called Seasonique about 2 weeks ago. My periods were not all that irregular, but irregular enough that it caused me to worry sometimes. I'm sexually active, and even though we always use protection, when a period is 2 weeks late sometimes (give or take), it still makes me worry sometimes. I'm getting married a year from now, so I also want to already be on a birth control that I know will work. I don't want to have to keep changing birth control pills as a newlywed. As I said, I've only been on Seasonique for 2 weeks, but so far I've had no problems. In case you're wondering the difference between the two, Seasonale has a week of inactive pills, and Seasonique contains low-dose estrogen pills during the last week instead of the inactive pills.