Can axiety/panic disorder and stress cause a late period? i've been havin bad panic problems for days on end right now. so i'm just wondering.

Yes. : Anxiety and stress are most common causes of irregular periods.

Possibly: 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.