Reoccurring miscarriages

Has anyone actually found the cause of their reoccurring miscarriages? I’m getting blood work done tomorrow & I’ll have my next appointment on Valentine’s Day. I’m nervous. Could vitamin deficiency play a role? I notice my teeth hurt every once in a while & my toe nails have white chips in them, I’m very tired all the time. I had an iron problem with my first pregnancy.. I hope it’s nothing major. Ever since I had my daughter I’ve had health issues, pericarditis, joint pain, neck problems, fatigue. Still haven’t found the cause but have a feeling it’s autoimmune related just never got the right testing done. I’ve had 4 miscarriages last year. 2 missed miscarriages. The most recent ones the heart beat was very low & I miscarried 2 weeks later at 8 weeks. The last one, Baby stopped growing at 5 weeks & I didn’t find out till I was supposed to be 10 weeks. So I don’t have an issue getting pregnant I just am having trouble keeping the pregnancy past 5 weeks… Can you tell me your experience & results?