I have a patch of darker skin that has slowly appeared on my forehead. I thought this was due to years and years of childhood sunburns finally coming back to kick me in the ass, but turns out it's due to birth control. My mother's friend said that as soon as she saw it that's the first thing she thought. So basically anyone who sees me will be able to see that I am taking birth control because it is stamped onto my forehead. Wonderful.