Mild cramps, bloating and not pregnant , and 10 days pass from due date of menses but no blood. and no pregnancy . what is this?

I don't know what it: is. Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, significant illnesses, oral contraceptives & other meds, Illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., PCOS). Pregnancy is #1 reason.