Mirena coil

Please can I have reviews on this method of contraception. I have been on a pill for nearly a year now however, my period pains have not calmed down - instead I am very emotional on it, get a lot of spots and my sex drive is low. Is it worth changing the contraceptive method? I still expect to have my period regulary and I've read that it may not be the case so I thought I'd ask for advice.  
Experiences? Please help...