What Are The Side Effects Of Mirena IUD?

hello i had the birth control called mirena and i had it removed about 3 or 4 years ago and i havent had a regular period since then and i have been tring to get pregnant so i was wanting to know did the mirena mess me up from getting pregnant or what can i do to get pregnant and i went to my doctor and she said i'm ok and she gave me medicine to start my period and thats been a while back and i still cant get pregnant can you please help me