If you're less than eight weeks pregnant when you have the miscarriage of the baby then you'll have expelled tissue that will look no different from heavy menstrual bleeding.
If you're further along in that during your pregnancy then you might or might not see expelled tissue that looks like a fetus or embryo.
You'll also have heavier bleeding and cramps the further along you are in pregnancy when you miscarry the baby.
Sometimes the fetus never comes out of you after a miscarriage and you may need to have surgery performed to remove the miscarried baby.