What Causes Delay In Menstruation Other Than Pregnancy?

LAST 3 MONTHS I AM IN PERIOD PROBLEM JAN 4 MY PERIOD DATE BUT NOT COME SO EAT ANANAS EAT THE COME 10JAN NEXT MONTH FEB 06 NORMAL NOW THIS MONTH NOT COME MAR 2 3 I EAT ANANAS THEN I EAT INDIAN TYPE HEAT FOOD FINALLY 8 I EAT ANANAS BUT NOT COMING I AM VERY STREES I AM TOTALLY ABSET ACTULLY WHAT MY PROBLEM TELL ME PLEASE