birth control
"I got the Skyla IUD in about 2 hours ago. Some background on me: I'm 21, 5'4, 125 lbs, and childless! I've never been on ANY long term medications, only antibiotics when I've gotten sick. Never been on birth control. 
I have taken plan B three times in the past 5 years and I have no adverse side effects from that. I was extremely nervous getting this because of the horror stories. Insertion was fine. The pinch on your cervix gets your attention, and then it feels like one or two big cramps when they measure the uterus and then insert the IUD. And then light cramping after. I felt a little hot and a little light headed afterwards and just lay there for about 5 minutes. Slight cramping now but it's barely noticeable! I'm so calm and relieved!"