With that being an IUD, you shouldn't have any problems getting pg unless you have some underlying issues. According to their website: "Studies show a woman’s chances of getting pregnant after Mirena is removed are similar to women who had not been using any form of birth control."
I have had problems trying to get pregnant since having my Mirena removed. I have had 5 healthy pregnacies. No problems what so ever.
Had the Mirena for 2 years. Had it removed Aug 2010 miscarried September 2010 at 5 weeks. Just now (Jan 2011) got a menstrual period and we are ttc again. This has been a true nightmare and I tell everyone who listens that if they want more children DO NOT get the Mirena.