I had a miscarriage 2 years ago, and I have been trying to get pregnant for 9 months now, Ik when I ovulate. I'm only 23. What's wrong?

See REI. There is no way to know what is wrong in your case. You need special testing. Fertility is a complicated issue. It would be best for you see an Ob/Gyn or Reproductive Endocrinologist (REI) for testing to determine the cause. Best wishes!