It has almost been 3 months since i last had my period. my last period was dec 4 and it only lasted 2 days i know pregnant is a possibility but what else?

Lack ovulation : Pregnancy and lack of ovulation would be the commonest causes of no period. Many reasons for lack ovulation including abnormal thyroid or diabetes or overweight or stress. I recommend my patients in this situation be seen to check this out.

Missed periods: 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. Get medically checked.