Levonorgestrel
"I got my Skyla in August of this year. I previously had the Nexplenon and loved it. I'm 24, never had children and had not had period from 6/2014 to 8/2016. I was not informed to take any kind of muscle relaxer or anti-inflammatory beforehand. The insertion was terrifying and painful. The "test" probe hurt so bad that I pushed out the speculum. Which meant that they had to start all over. The cramping was painful and I was so glad I did it on a Friday. Since insertion, I have had a period every month and the cramps are excruciating. I also get sharp pains when I am not on period. I called the doctor today and told them what was going on. They told me that I need to go back to the Nexplenon asap."