This will usually be noted on your chart as a missed abortion. 

You will often be given as much as two weeks to see if a natural miscarriage will begin. After those two weeks, you can usually request a D&C and receive it. Some doctors will advise or allow a D&C immediately if you prefer. Occasionally, if you meet certain qualifications with your hCG levels and size of the baby when it stopped growing, you may receive a shot and/or suppositories to bring on a natural miscarriage. This can only be done if the pregnancy was less than seven weeks in measurement, and is not yet widely offered because it may require you to wait three months before attempting to conceive again.

Sometimes spotting will begin within 24 hours of your learning of the loss. Even though the baby may have died weeks earlier and the body has not reacted, somehow the actual knowledge that the pregnancy is ending will make the hormone levels start to fall.

Often, however, a loss where the baby has died weeks before the diagnosis will not resolve without a D&C. Give yourself a couple of days to cope with what has happened, and then schedule the surgery. If your doctor is resistant to surgery and you want it, it is time for a new doctor. Keep in mind that this situation should not go on for more than three weeks or complications can result, including infection.

See also:
What is a natural miscarriage like?

and

What is a surgical D&C / D&E like?