After plan b got 2 regular periods and 3rd one is late and i started urinating frequently. i had -ve tests after 1st and 2nd one. i am worried nw. ?

If you have had: 2 normal periods since your last sexual activity then you should not be pregnant at this time. 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)