Does eating bad cause miscarriage?

I am 6 weeks with my first. I generally eat pretty healthy and have continued since I found out I was pregnant.

For the last week, I have had ice cream every single night after dinner and today i at a frozen single (small) pizza, bag of chips for lunch and a few skittles. I want to get a sub from penn station and fries later because I am craving it badly.

Again, I eat healthy normally but have been craving some junk. Should I stay away?

Can this harm the baby or cause a miscarriage? I am terrified to do anything wrong