Birth Control

So I recently checked my IUD strings yesterday, (I have the Kyleena) and I felt them and nothing seemed out of the ordinary. Today for some reason I decided to check them again since I finished my period earlier today, and I could not feel my strings AT ALL. I'm freaking out a little bit because I'm scared my IUD might have come out without me noticing. I read that sometimes the strings can curl up but I'm so scared that it came out. Does anyone have any similar experiences or some advice PLEASE!