Birth Control
"I had Nexplanon inserted on Nov. 20, 2016. It is Jan. 20, 2016 and I have bled every single day. There was a week of much heavier bleeding and maybe two weeks of moderate bleeding, the rest have been light to moderate without stopping. 
Some research suggests that Ibuprofen every 6 hours as prescribed or Doxycycline twice a day as prescribed will help to settle the endometrial lining however, neither has worked for me."