Confused

I am supposed to be 8 weeks today. Been having some spotting in the mornings, but then it stops like clockwork. Today went for my first prenatal appointment, and OB said that when she examined me that I'm either on the verge of a miscarriage or I have a polyp. They sent me to get an ultrasound and doctor said I'm measuring at 6 weeks. Didn't say anything about a miscarriage. I have to go back and get another viable ultrasound. I'm just scared and freaked out.