Crohn's disease and TTC

My question is what is stopping me from getting pregnant. I haven't taken any mess for crohns since probably January (even then it was just antibiotics and prednisone) before that it's been almost two years since I took humira for 4 months. I haven't been in flare since January but had a chemical pregnancy in April and not a thing since??! Why? I have never had surgery for Crohns had a pelvic ultrasound a couple months ago doc said it was all good. Periods are pretty regular so what's wrong???