Thanks for query,
You have delayed bleeding.
Delayed bleeding occurs due to hormonal
Hormonal imbalance occurs due to stress
,Shift duty,long night working hours,or some ovarian lesion.
When you get delayed bleeding you get bits of endometrium with clotted blood with it.
If you do not get next regular cycle for 2--3 cycle you should consult your doctor for differential diagnosis.
He will suggest you the measure as per result of examination.