I'm pretty sure I'm having a miscarriage

So yesterday I went to he Dr to get my first Ultrasound. I was bleeding a little before I went. Well they told me I was measuring 6 weeks. I'm suppose to be around 9. The ultra sound tech said " I'm sorry this may just be a bad pregnancy." I really think they need to train them on sensitivity. I started bawling. I have been bleeding and cramping for 2 days It's not filling a pad but there is red blood every time I wipe. Do I wait and let it do it on its own or go to the dr. And get a pill to help it or go ahead and get a D&C;? I don't know anything about having a miscarriage. I'm so saddened by all of this. I don't know what I'm doing.