I had relplied on a previous post about mirena...here is my opinion on it:
I have had my mirena for a little over a year. At first I was very unhappy with it and almost had it removed. I had severe cramping from the moment it got put in for about 8 months after. The cramping finally subsided and hadn't had any problems since for the most part. I do get real crampy once a month and they are pretty bad cramps. They last about a week and then are gone until the next month. I had my iud inserted while on my period (doc said to) and the bleeding stopped immediately after insertion and I have not had a period since that day!!! That I love. I forget that it is even there. I had so many problems with other methods of bc. The pill was too hard for me to remember to take and gave my high blood pressure and so did the nuva ring which was just a pain in the butt. Always slipping out and moving around, etc. So I have to say overall I am pretty happy with the mirena. I'd give it a little longer before you give up. Like I said mine took atleast 8 months and when I mentioned it and saw my doc she said that it is just different in some women. I wouldn't switch bc for anything!