Period? Or misscarriage? I don’t know.?

I was put on Nexplanon birth control on November 12th and havent had a period since December 20th. I’m very sexually active, and i started bleeding today. What could this be. Thanks!

Popular: 7 Tips to Stay Healthy and Fit 8 Game Changing Tips and Tricks with Carrots for Gorgeous Skin, Hair and Body Fight Your Holiday Fat! 5 the Deadliest Diseases Ever in Human History 5 Tips on How to Stay Healthy This Winter