Despite how it is often depicted in the media, a first-trimester miscarriage usually does not happen all at once. The baby usually has already passed away by the time the physical symptoms of miscarriage appear, sometimes more than a week before. The miscarriage bleeding may begin as light spotting and then progress to a heavier flow with clots after a few days. You may have some level of bleeding for up to two weeks, although it should not remain heavy for that entire time.
All in all, the precise timing of how long a miscarriage lasts is fairly unique for each woman, as it depends on a couple factors. For instance, in one scenario, a woman might start bleeding a few hours after getting the diagnosis and, in another scenario, the miscarriage process might not begin for several weeks, even if the pregnancy is not viable.
That said, research shows that you’re most likely to start and finish bleeding within two weeks of the diagnosis.
It’s also important to note that after a miscarriage diagnosis, a woman may opt to manage her miscarriage medically or surgically (for example, a D&C), and this also affects the duration of symptoms. For example, after a D&C to manage a miscarriage, a woman may experience light bleeding or mild discomfort, but not heavy bleeding or abdominal pain. If this happens, a woman should contact her doctor right away.