I been on birth control (IUDs) mirena (levonorgestrel) for 10 yrs I been trying to get pregnant for over a year why hasn't it happened? Could the IUD be the reason

Long changes. With 10 years of near constant progesterone presence in your uterus with the Mirena (levonorgestrel) IUD in place, I have to think that it's going to take your body awhile to readjust to get back to "normal" levels of it's own hormones and cycles. Patience is difficult to have when you're trying to conceive but give your body some more time and keep trying. Consider using ovulation kits to know exactly when to try.