Job also asked why, but never got an answer. Someone mentioned Psalm 37, which has been my personal meditation lately, particularly verse 4. I read a devotional where a woman and her husband also had issues getting pregnant. After a while, she learned to be content by diving into ministry and service. At 38, she discovered she was unexpectedly pregnant. So perhaps you need to learn this as well. The bible talks about the Lord dealing with infertility several times. Don't quit praying, just learn to be content now. Enjoy your husband and find things to be involved in that will help keep you distracted.

Hope this helps.