Y is my cervix closed if i am miscarrying from blighted ovum&why does my doctor want to test my hcg levels? also i've barely bled & it's been a week

Blighted ovum: In a normal spontaneous miscarriage the hcg level should continue to fall as the cells which produce hcg die off. In rare cases something called a molar pregnancy develops. In a mole hcg levels would continue to rise and in very rare instances can develop into a malignancy called choriocarcinoma. Your doctor may need to perform a D&C to remove the remnants of this pregnancy. Talk with your Dr