Mirena users I could use your advice please

Last Friday on the 13th, I had the mirena iud inserted to help with bad periods. It's the only birth control that helps with periods that I'm not allergic to... It's been almost a full week since I've had it inserted and I am still spotting and when I sit up straight or bend over, I feel a slight pressure in my uterus. It doesn't hurt, it's just a little pressure that's annoying. I have also noticed a decrease in my sex drive which is usually high. Is this normal and my body is still adjusting to the iud or should I go back to the doctor? Any help or advice is appreciated