Im 4 days late. on day two i testes neg and this morning i retested and got a question mark on the test. what should i do. can i buy another n test same day?

HPT: You can retake in a week or less using first morning void. 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).