D.B.
Welcome to Mamapedia. I don't blame you for feeling confused and worried. Early pregnancy is such a tough time. And there are all kinds of things like bleeding and cramping that can mean something bad, or just something annoying that will pass.
I do think you should call your doctor and not worry so much about waiting the 2 weeks for the next test/visit.
Yes, many pregnancies end in miscarriage. There are many reasons, and sometimes there are just no reasons that we ever know. But listen, no matter what, you are NOT causing this by worrying too much. Yes, your hormones are affecting your worries to some degree, but your symptoms are very real and they are so difficult to categorize (what caused what).
Call your doctor, and tell him/her you need to see a counselor familiar with pregnancy issues to help you through this difficult time. There are also massage therapists who specialize in pregnant women and who can help to ease some of your stress.