My wife currently has a mirena (levonorgestrel) iud and going on the 6th year. she is already 34 and healthy. what are the chances she can get pregnant if we plan after 2-3 years if she gets her iud removed now?

Depends: A IUD is a device for contraception. It basically creates a hostile environment for a fertilized egg. Once it is removed fertility should return immediately. However your wife is now 6 years older! It is known that female fertility declines with age, just why unsure. That can probably be dealt with better by non medical interventions-I.e. Candle light dinner, great music, listening to her, etc.

Depends: Has she been pregnant before? Are her menstral cycles regular? Did she ever have any vaginal infections? Do you have a normal sperm count? Lots of couples have kids in their 30's, even 40's, but even in 30's fertility for both starts to decline. My suggestion: don't wait. If you have trouble conceiving you'll have more time to try when younger. 34 is likely more fertile than 38 for both of you.