Etonogestrel
"I'm 17, and this is the first type of birth control I've tried. I got it inserted in October of 2013, and have been bleeding ever since. It's not heavy, and I don't experience any cramps. Although it's still a huge annoyance. I have experienced a lot more acne problems than before, I had completely clear skin, and now I get painful, large pimples. I have gained a little weight, but I'm quite skinny, so I don't mind. I haven't noticed any more mood swings than normal, I am a teenager and that teds to happen a lot anyway.  
I've had it in for about 5 months, and my doctor told me I might experience bleeding for up to 6 months. If it continues after 6 months I plan on getting it removed."