I had my period on 8/31/13 ended on 9/5/13 . usully my period comes in every 21 days . my pms came on 10/4/13. im 10 days late. can i be pregnant ?

Possibly - take a : Home pregnancy test. Reasons for missed/late periods: low body weight, obesity, marked weight ^ or v, over-exercise, endurance athletics, breast-feeding, ^ stress, illness, eating disorders (bulimia or anorexia), anovulatory cycle (no egg released), travel, hormone irregularities, drug use, meds (i.e., birth control) or medical problems. #1 reason is pregnancy.

Pregnant?: Yes , it is possible that you are pregnant if you had intercourse. Start doing home pregnancy tests which will reveal a pregnancy as early as one period is skipped, .