WHY CANT I GET PREGNANT!!

I am 20 years old, My husband and I had a miscarriage this last January. I was 15 weeks pregnant and the baby died at 10 weeks. I had a d&c; and then there were complications during the surgery and I had to have a blood transfusion. We were devastated, and I was absolutely heartbroken, this being my first and only pregnancy, I went through serious depression and suicidal thoughts. After trying to get help and starting to heal, we decided to start trying again, we have been trying for about 4 months and I don't know why I got pregnant so fast and easy the first time (it only took one month) but now it's taking longer. I'm worried and nervous. Is it normal? How long before you got pregnant again? 💔

My baby would have been due on July 21st this month. And I'm taking it kinda hard...