A study of 1.8 million Danish women (for those keeping track, that’s almost a third of the country’s population) found that birth control pills may lead to an increased risk of breast cancer. That news isn’t surprising in of itself, there have been studies alleging link this for years. But because the study was so large, researchers were able to see if newer birth control pills—which use lower doses of hormones than older pills—also had the same link, which they did. Same for IUDs that use hormones. No need to worry too much though, the risk is pretty tiny, and increases with age. If you’re concerned, you can ask your doctor about switching to a non-hormone based contraceptives.