I have brown spots and cramping .im 10 weeks pregnant and 3 days . i went to the hospital and the us shows low lying placenta grade 0 . what to do ?

Nothing: At 10-11 weeks pregnant it is common to have a low lying placenta. They usually "migrate" upward and away from the cervix as the uterus grows and the pregnancy progresses. If everything else was normal on the ultrasound and there was a normal heartbeat, there is every reason to expect a normal pregnancy. Some doctor do recommend having nothing in the vagina if you are spotting.