Etonogestrel
"I have had nexplanon for almost a month now and I am experiencing sharp pain shooting up my arm into my left breast. It is also burning my arm. Every now and again it will stick out my arm and it looks like a knot in my arm. If my shirt touches it the wrong way it will start hurting really bad. I got it put in on Sept 15 and I have started bleeding 7 times since I have had it"