How long does it take to miscarry after you don't hear heartbeat?

Generally within wks: Unfortunately we cannot pinpoint a date for several reasons. One, we cannot always determine when the fetus ceased having a heart beat. Two, the cause of the loss or coexisting conditions (eg, infection or bleeding) can affect how quickly one passes the fetus etc. Three, every woman/pregnancy is different. Finally, some women do not pass all tissue for weeks or might need a doctor's intervention.

It varies: It can take a while for the body to realize the baby is no longer alive. So it takes a variable amount of time, from a few days to several weeks. The uncertainty is hard to deal with at times, so some women get medication to speed the process & some have a d&c. Waiting is a good option for some, too. It's your choice as lon as there are no complications, like bleeding or pain.