Endometrium is sometimes shed as a whole during menstruation
when there is some amount of endometritis; this can be viewed as a piece of flesh. The other possibility is a chemical abortion
, wherein an abortion can happen even before a pregnancy
can be clinically diagnosed. This is due to some genetic or hormone defect. The exact reason can be identified only if you can get the discharge analyzed histo-pathologically. A blood test
for pregnancy is also helpful. Hope you find this information useful. Take care.