Adjustment phase after Mirena IUD?

Hey everyone. So 5 days ago I got the Mirena IUD. I've had cramping and spotting, which I know is normal, ever since. It feels like the first day of my period every day now, just without the large amounts of blood. I also feel sad more than normal, especially at night time. I've never been on any form of birth control before. I don't know if my feeling down is caused by the IUD though because I know that it's a very small amount of hormones. Has anyone had a similar xperience? How long did your adjustment phase last?