Please ignore the response from quasha72. I don't know what your doctor meant and how it related to the type of biopsy he was trying to perform. You should question him.
Often we refer to a cervix being closed, and it is what we consider to be normal whether pregnant or not. This doesn't mean one cannot get pregnant, as despite being "closed" sperm can still pass through microscopic passageways (and sometimes bacteria as well causing infections).
that is probably why you dont have any kids. that is why most women have miscarriages, their cervix closed afterwards.