Skyla IUD

So I had the skyla put in after I had my little girl. Now it's a little over a year and I started having cramps (which I haven't had any since I got the iud) these cramps weren't horrific but they were annoying. I checked my strings the other day and they were super long. I made an appointment to go see my gyno just to check if everything was where it was supposed to be. This morning I was cramping a little bit and went to check my strings and the iud FELL out. I didn't pull on the strings or anything. It was literally just hanging there.

My question is: Has this ever happened to anyone else?

Should I still go see my doctor or just go on with my day?