Miscarriage

I had my miscarriage at 6 weeks a few weeks ago. I know doctors tell us that it’s common and sometimes it just happens and nobody knows why but I am very much the kind of person who needs a reason or needs possible reasons so that I can try to help lower my chances next pregnancy.( also, I’m 23 and I have had one healthy full term pregnancy with my daughter who is now 4) I know I’ll be scared when and if I conceive again but I’m hoping some of you guys can help me. I am currently working as a janitor and Work with some chemicals but not a lot. When I found out I was pregnant I continued to wear gloves like I always do and wore a nose and mouth mask but for some reason I feel like that contributed to it and also at that time had my cats litter box in our room but away from our bed (my fiancé changed litter not me). I don’t really have any real questions.. I just need some words of wisdom and experience to ease my mind I guess... god is good but this doesn’t feel good at all. My mind is my worst enemy.