Can't find strings

Hey so I haven't posted here before but I was hoping for some advice. I've had my IUD in for 4 months. I haven't checked my strings since my dr did it when I first got it in. I don't normally touch myself or anything and I'm not super sexual so I'm not sure if I'm not doing it right but I can't find my strings how high up am I supposed to go cause I can't go Any further and I can't find them. Please help I know this is long.