Hi teegandm11 welcome to HCM,
These are not the signs of displacement of mirena
IUCD but the pain you have described may occur as e side effect of mirena, it may also be due to pelvic infection
and inflammation which needs to be evaluated seriously as it may lead to infertility
and other complications..
Random, sharp lower back pains may also occur due to Lumbar spine
problems, ureteric stones and some other conditions. So its better get yourself examined once...