Levonorgestrel
"I had Skyla inserted 6 months ago and I like it.  The insertion was uncomfortable and somewhat painful.  I did bleed for a few days after but nothing outside of the normal. I will say now, my cycle is all out of whack. It's irregular and super light to the point where I only use a pantyliner.  This does freak me out because I'm always papranoid about getting pregnant while using Skyla and not knowing it.  I think I know my body well enough to know I'm not, but you know your mind gets the best of you.  Overall, I love not having to remember a pill everyday... I have a 2 year old thanks to BC pills so no thank you. IUD is definitely better!"