Can you get pregnant on mirena (levonorgestrel)? If so will a pregnancy test show or will your body send out the wrong hormones because of mirena (levonorgestrel)?

Not likely. Remember, nothing is 100% effective, but having a well placed Mirena (levonorgestrel) is >98% effective. A positive test will still occur in case of pregnancy & if it does happen, see your doc asap so your pregnancy can be evaluated & the Mirena (levonorgestrel) removed. It's normal to skip menses and a negative pregnancy test can be trusted, so relax.
Yes. It is possible to achieve pregnancy with a mirena (levonorgestrel). The pregnancy test would still function in a normal way. The hormonal support of the pregnancy could be adversely affected due to the progestin in the mirena (levonorgestrel).