I am 5.5 weeks along and went to the hospital last night because I have been cramping more and bleeding a little more brown blood. The doctor did an ultrasound and couldn't see anything in my uterus. I have to go back today and get one of those ultrasounds where they stick it up your vagina (don't remember what it's called) to see if it's either a miscarriage or the baby is too small to see. Has this ever happened to anyone ?