Trying to figure out why

Here are my irrational thoughts of why I m/c'd:
1) Caffeine: I've always told myself that I would not drink caffeine if I got pregnant. I drank a ton of coffee before my BFP and then I had a tiny bit of coke on the day I m/c.
2) Microwaves & massive printer/copier at work
3) Huge fight/argument w/ DH.
4) Terrible stomach flu 10 days before BFP when I didn't eat for 3 days.
5) I used all kinds of cleaners/chemicals the week I m/c, cleaning in prep for my in-laws to visit.
6) I wasn't excited enough when I found out I was pregnant.

I also have the terrible feeling that maybe I could have prevented the m/c by going to the ER when I started spotting, before the bleeding got too bad. It was all over by the time I saw my doctor.