About 8 weeks pregnant an my stool is black an sticky an smells like a litter box?

Black stools. The iron that is in many prenatal vitamins can cause black stools.This is the most likely cause of ur problem but tell ur OB about this on your next visit since blood in ur bowel movement can also cause black tarry stools. Even though it is much less likely it can be serious and is easy to test for and rule out. You may be better off with another prenatal vitamin as long as u get ur dietary iron.