Good day.... i went off the pill end of feb 2020. i had my period for a little 3 days and then it ended... this month i am 18days late already. did do a pregnancy test which came back negative. what is the possible reason?

Possible reasons: Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, significant illnesses, oral contraceptives & other meds, Illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., PCOS). Pregnancy is #1 reason.