Need some advice/ encouragement.... lost baby last September at 19 weeks

I get worried I won't get pregnant again. My boyfriend says he wants another. That baby boy I lost would've been our first together, we each had one from previous relationship. My son is 9 and will be 10 in October, I Also will be 33 in October. During that pregnancy I had a lot of pain. Found out through a colostomy at 14 weeks I have Crohn's disease and colitis. Also I had a 10cm cyst on my left ovary. And after my 4 month post check up the cyst is still there. But the MD isn't concern. He says I can try again and they will close up my cervix at 12 weeks. They was gonna do it anyway at 20 weeks since all the issues I'm having also o had my son at 34 weeks. Im so worried I wanna be prego now. But it's hard to track ovulation since now my periods have come at 26-27 days. Before I was pregnant it was about 32 days...