My period is 4 days late. i took 6 pregnancy tests. allwere negative. what could be wrong?

Could be nothing!: Delayed menstrual cycles not unusual. Stress, hormone or weight changes can cause this. Check pregnacy tedt in a week if still no period!

A/W Dr. Anissian: 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 (i.e. PCOS). #1 reason is pregnancy.