Is it ok to get pregnant right after having the Mirena (levonorgestrel) IUD removed?

Yes. The Mirena (levonorgestrel) should have no impact on your ability to get pregnant and carry a pregnancy. I am however worried about your age and suggest that you see an OBGYN to discuss the risks/chances of your getting pregnant in order to optimize your chances.
Wait one month. You can get pregnant right after removal, however consider waiting one normal cycle first. This will allow your endometrial lining to be a more normal thickness (it gets thinner with mirena) and you may have a lower risk of early pregnancy bleeding.